Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005737 cytoplasm	IBA GO_REF:0000033	ACCEPT	Summary: cytoplasm localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0031624 ubiquitin conjugating enzyme binding	IBA GO_REF:0000033	ACCEPT	Summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0006511 ubiquitin-dependent protein catabolic process	IBA GO_REF:0000033	ACCEPT	Summary: ubiquitin-dependent protein catabolic process is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0061630 ubiquitin protein ligase activity	IBA GO_REF:0000033	ACCEPT	Summary: ubiquitin protein ligase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0000151 ubiquitin ligase complex	IBA GO_REF:0000033	ACCEPT	Summary: ARIH1 forms functional ubiquitin ligase assemblies with neddylated CRLs; this broad complex annotation captures that E3-ligase-complex context. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005634 nucleus	IBA GO_REF:0000033	ACCEPT	Summary: nucleus localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0004842 ubiquitin-protein transferase activity	IEA GO_REF:0000002	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0005634 nucleus	IEA GO_REF:0000044	ACCEPT	Summary: nucleus localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005737 cytoplasm	IEA GO_REF:0000044	ACCEPT	Summary: cytoplasm localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0008270 zinc ion binding	IEA GO_REF:0000002	ACCEPT	Summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3 mechanism, so zinc ion binding is supported. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0015030 Cajal body	IEA GO_REF:0000044	KEEP AS NON CORE	Summary: Cajal body is retained as a reported localization or colocalization but is not part of the core ARIH1 ubiquitin-ligase mechanism. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Nucleus, Cajal body file:human/ARIH1/ARIH1-uniprot.txt Present in Lewy body
GO:0016567 protein ubiquitination	IEA GO_REF:0000120	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0046872 metal ion binding	IEA GO_REF:0000002	MODIFY	Summary: The metal-binding evidence is specifically zinc binding by RING/IBR/RING domains; the broad metal ion binding term should be replaced by zinc ion binding. Reason: Specific zinc-binding domains are known; the generic metal ion binding term is less informative. Proposed replacements: zinc ion binding Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0061630 ubiquitin protein ligase activity	IEA GO_REF:0000003	ACCEPT	Summary: ubiquitin protein ligase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0005515 protein binding	IPI PMID:21145461 Dynamics of cullin-RING ubiquitin ligase network revealed by...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005515 protein binding	IPI PMID:21532592 UBCH7 reactivity profile reveals parkin and HHARI to be RING...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005515 protein binding	IPI PMID:23707686 Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoin...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005515 protein binding	IPI PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005515 protein binding	IPI PMID:28514442 Architecture of the human interactome defines protein commun...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005515 protein binding	IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005654 nucleoplasm	IDA GO_REF:0000052	ACCEPT	Summary: nucleoplasm localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0039585 PKR/eIFalpha signaling	TAS Reactome:R-HSA-9833482	KEEP AS NON CORE	Summary: PKR/eIFalpha signaling is a pathway-level consequence in Reactome rather than the core molecular role of ARIH1; keep it as non-core while prioritizing ubiquitin/ubiquitin-like ligase activity. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916).
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169394	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169395	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169398	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169402	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169405	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-1169406	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0061662 ISG15 ligase activity	TAS Reactome:R-HSA-9833973	KEEP AS NON CORE	Summary: ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:23707686 Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoin...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0005737 cytoplasm	IDA PMID:23059369 Human Homolog of Drosophila Ariadne (HHARI) is a marker of c...	ACCEPT	Summary: cytoplasm localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0008270 zinc ion binding	IDA PMID:23707686 Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoin...	ACCEPT	Summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3 mechanism, so zinc ion binding is supported. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0016567 protein ubiquitination	IDA PMID:23707686 Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoin...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0016567 protein ubiquitination	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0016567 protein ubiquitination	IDA PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0016604 nuclear body	IDA PMID:23059369 Human Homolog of Drosophila Ariadne (HHARI) is a marker of c...	KEEP AS NON CORE	Summary: nuclear body is retained as a reported localization or colocalization but is not part of the core ARIH1 ubiquitin-ligase mechanism. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Nucleus, Cajal body file:human/ARIH1/ARIH1-uniprot.txt Present in Lewy body
GO:0019005 SCF ubiquitin ligase complex	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	ACCEPT	Summary: SCF ubiquitin ligase complex association is part of the best-supported ARIH1 mechanism: ARIH1 cooperates with neddylated SCF complexes as a catalytic E3-E3 super-assembly for CRL substrate ubiquitination. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0019005 SCF ubiquitin ligase complex	IDA PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	ACCEPT	Summary: SCF ubiquitin ligase complex association is part of the best-supported ARIH1 mechanism: ARIH1 cooperates with neddylated SCF complexes as a catalytic E3-E3 super-assembly for CRL substrate ubiquitination. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031462 Cul2-RING ubiquitin ligase complex	IDA NOT PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	KEEP AS NON CORE	Summary: This NOT-qualified Cul2-RING complex annotation is retained as a non-core, experiment-specific negative result from PMID:27565346, but it conflicts with positive CUL2 interaction evidence from PMID:24076655 and with UniProt text citing both PMID:24076655 and PMID:27565346 for neddylated CUL2 interaction. The most defensible interpretation is context-dependent assay behavior rather than a global absence of CUL2 association. Reason: Preserve the GOA NOT qualifier while explicitly flagging the conflict with broader positive CUL2 evidence. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031462 Cul2-RING ubiquitin ligase complex	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	KEEP AS NON CORE	Summary: Positive Cul2-RING complex association is retained as a non-core CRL context for ARIH1. This should be read alongside the separate NOT-qualified PMID:27565346 annotation, which likely reflects a context-specific negative assay rather than a global absence of CUL2 interaction. Reason: ARIH1-CRL cooperation is well supported, but individual cullin-complex annotations are context annotations rather than the core catalytic function. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031463 Cul3-RING ubiquitin ligase complex	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	KEEP AS NON CORE	Summary: Cul3-RING ubiquitin ligase complex association is supported as a CRL partnership for ARIH1; it is retained as a non-core complex context rather than the core catalytic activity itself. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031463 Cul3-RING ubiquitin ligase complex	IDA PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	KEEP AS NON CORE	Summary: Cul3-RING ubiquitin ligase complex association is supported as a CRL partnership for ARIH1; it is retained as a non-core complex context rather than the core catalytic activity itself. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031464 Cul4A-RING E3 ubiquitin ligase complex	IDA PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	KEEP AS NON CORE	Summary: Cul4A-RING E3 ubiquitin ligase complex association is supported as a CRL partnership for ARIH1; it is retained as a non-core complex context rather than the core catalytic activity itself. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031624 ubiquitin conjugating enzyme binding	IPI PMID:23707686 Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoin...	ACCEPT	Summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0031624 ubiquitin conjugating enzyme binding	IPI PMID:24076655 TRIAD1 and HHARI bind to and are activated by distinct neddy...	ACCEPT	Summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0031624 ubiquitin conjugating enzyme binding	IPI PMID:27565346 Two Distinct Types of E3 Ligases Work in Unison to Regulate ...	ACCEPT	Summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0097413 Lewy body	IDA PMID:21590270 The parkin-like human homolog of Drosophila ariadne-1 (HHARI...	KEEP AS NON CORE	Summary: Lewy body is retained as a reported localization or colocalization but is not part of the core ARIH1 ubiquitin-ligase mechanism. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Nucleus, Cajal body file:human/ARIH1/ARIH1-uniprot.txt Present in Lewy body
GO:0005829 cytosol	TAS Reactome:R-HSA-1169394	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169395	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169398	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169402	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169403	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169405	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1169406	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-1678843	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-9833973	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-9837231	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0005829 cytosol	TAS Reactome:R-HSA-9927247	ACCEPT	Summary: cytosol localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:14623119 Human homologue of ariadne promotes the ubiquitylation of tr...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:15236971 Structure of the C-terminal RING finger from a RING-IBR-RING...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0004842 ubiquitin-protein transferase activity	IDA PMID:21532592 UBCH7 reactivity profile reveals parkin and HHARI to be RING...	ACCEPT	Summary: ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine to substrates. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0005515 protein binding	IPI PMID:14623119 Human homologue of ariadne promotes the ubiquitylation of tr...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0005737 cytoplasm	IDA PMID:11278816 Features of the parkin/ariadne-like ubiquitin ligase, HHARI,...	ACCEPT	Summary: cytoplasm localization is supported for intracellular ARIH1; the most relevant functional locations are cytoplasm/cytosol and nucleus. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF).
GO:0008270 zinc ion binding	IDA PMID:15236971 Structure of the C-terminal RING finger from a RING-IBR-RING...	ACCEPT	Summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3 mechanism, so zinc ion binding is supported. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt bind E2s via the first RING-type zinc finger
GO:0016567 protein ubiquitination	IDA PMID:14623119 Human homologue of ariadne promotes the ubiquitylation of tr...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0016567 protein ubiquitination	IDA PMID:15236971 Structure of the C-terminal RING finger from a RING-IBR-RING...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0016567 protein ubiquitination	IDA PMID:21532592 UBCH7 reactivity profile reveals parkin and HHARI to be RING...	ACCEPT	Summary: protein ubiquitination is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0031625 ubiquitin protein ligase binding	IPI PMID:11278816 Features of the parkin/ariadne-like ubiquitin ligase, HHARI,...	KEEP AS NON CORE	Summary: Specific binding to ubiquitin ligase complexes is supported through ARIH1 cooperation with neddylated CRLs, but it is a complex-association context rather than the primary catalytic function. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0031625 ubiquitin protein ligase binding	IPI PMID:21532592 UBCH7 reactivity profile reveals parkin and HHARI to be RING...	KEEP AS NON CORE	Summary: Specific binding to ubiquitin ligase complexes is supported through ARIH1 cooperation with neddylated CRLs, but it is a complex-association context rather than the primary catalytic function. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-uniprot.txt Associates with cullin-RING ubiquitin ligase (CRL) complexes containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with neddylated CUL4A (PubMed:24076655).
GO:0005515 protein binding	IPI PMID:10521492 The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact w...	MARK AS OVER ANNOTATED	Summary: Generic protein binding is over-broad for ARIH1. The informative interaction annotations are E2 binding and CRL/SCF association. Reason: Replace generic binding with mechanistically specific E2 or ubiquitin-ligase-complex binding where possible. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0000151 ubiquitin ligase complex	TAS PMID:10521492 The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact w...	ACCEPT	Summary: ARIH1 forms functional ubiquitin ligase assemblies with neddylated CRLs; this broad complex annotation captures that E3-ligase-complex context. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0006511 ubiquitin-dependent protein catabolic process	TAS PMID:10521492 The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact w...	ACCEPT	Summary: ubiquitin-dependent protein catabolic process is supported by the catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent substrate turnover, especially as a CRL-associated priming E3. Supporting Evidence: file:human/ARIH1/ARIH1-deep-research-falcon.md A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. file:human/ARIH1/ARIH1-deep-research-falcon.md In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate.
GO:0019787 ubiquitin-like protein transferase activity	TAS PMID:10521492 The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact w...	KEEP AS NON CORE	Summary: ubiquitin-like protein transferase activity is retained as a confirmed secondary ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated CRLs. Reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core activity synthesized from current CRL/RBR literature. Supporting Evidence: file:human/ARIH1/ARIH1-uniprot.txt Acts as the ligase involved in ISGylation of EIF4E2 (PubMed:17289916). file:human/ARIH1/ARIH1-deep-research-falcon.md older literature reported interaction with UBE2L3 and UBE2L6

Core Functions

RBR E3 ubiquitin-protein ligase activity that primes ubiquitination of CRL-bound substrates in neddylated SCF/CRL assemblies.

Molecular Function:

ubiquitin protein ligase activity

Directly Involved In:

protein ubiquitination ubiquitin-dependent protein catabolic process

Cellular Locations:

cytoplasm cytosol nucleus

In Complex:

SCF ubiquitin ligase complex

Supporting Evidence:

file:human/ARIH1/ARIH1-deep-research-falcon.md
A major current paradigm is that **neddylated CRLs recruit and activate ARIH-family RBR ligases**. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning.
file:human/ARIH1/ARIH1-deep-research-falcon.md
In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.

UBE2L3/UbcH7 binding as the E2-recruitment step of ARIH1 RBR ubiquitin transfer.

Molecular Function:

ubiquitin conjugating enzyme binding

Directly Involved In:

protein ubiquitination

Cellular Locations:

cytoplasm nucleus

Supporting Evidence:

file:human/ARIH1/ARIH1-deep-research-falcon.md
In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
file:human/ARIH1/ARIH1-uniprot.txt
bind E2s via the first RING-type zinc finger

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000003

Gene Ontology annotation based on Enzyme Commission mapping

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000052

Gene Ontology annotation based on curation of immunofluorescence data

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:10521492

The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact with RING finger/IBR motif-containing domains of HHARI and H7-AP1.

PMID:11278816

Features of the parkin/ariadne-like ubiquitin ligase, HHARI, that regulate its interaction with the ubiquitin-conjugating enzyme, Ubch7.

PMID:14623119

Human homologue of ariadne promotes the ubiquitylation of translation initiation factor 4E homologous protein, 4EHP.

PMID:15236971

Structure of the C-terminal RING finger from a RING-IBR-RING/TRIAD motif reveals a novel zinc-binding domain distinct from a RING.

PMID:21145461

Dynamics of cullin-RING ubiquitin ligase network revealed by systematic quantitative proteomics.

PMID:21532592

UBCH7 reactivity profile reveals parkin and HHARI to be RING/HECT hybrids.

PMID:21590270

The parkin-like human homolog of Drosophila ariadne-1 (HHARI) can induce aggresome formation in mammalian cells and is immunologically detectable in Lewy bodies.

PMID:23059369

Human Homolog of Drosophila Ariadne (HHARI) is a marker of cellular proliferation associated with nuclear bodies.

PMID:23707686

Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoinhibition of an Ariadne-family E3 and insights into ligation mechanism.

PMID:24076655

TRIAD1 and HHARI bind to and are activated by distinct neddylated Cullin-RING ligase complexes.

PMID:27565346

Two Distinct Types of E3 Ligases Work in Unison to Regulate Substrate Ubiquitylation.

PMID:28514442

Architecture of the human interactome defines protein communities and disease networks.

PMID:33961781

Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.

Reactome:R-HSA-1169394

ISGylation of IRF3

Reactome:R-HSA-1169395

ISGylation of viral protein NS1

Reactome:R-HSA-1169398

ISGylation of host protein filamin B

Reactome:R-HSA-1169402

ISGylation of E2 conjugating enzymes

Reactome:R-HSA-1169403

Interaction of E3 ligase with ISG15:E2 complex

Reactome:R-HSA-1169405

ISGylation of protein phosphatase 1 beta (PP2CB)

Reactome:R-HSA-1169406

ISGylation of host proteins

Reactome:R-HSA-1678843

ISGylation of protein translation regulator 4EHP

Reactome:R-HSA-9833482

PKR-mediated signaling

Reactome:R-HSA-9833973

ISGylation of PKR

Reactome:R-HSA-9837231

ISGylation of BECN1

Reactome:R-HSA-9927247

ISGylation of DDX58 (RIG-I)

file:human/ARIH1/ARIH1-deep-research-falcon.md

Falcon deep research synthesis for ARIH1

file:human/ARIH1/ARIH1-uniprot.txt

UniProt record for ARIH1

Deep Research

Falcon

(ARIH1-deep-research-falcon.md)

Research Report: Human **ARIH1 (HHARI)** Functional Annotation (UniProt Q9Y4X5) Falcon Edison Scientific Literature 30 citations 2026-05-11T21:17:56.306599

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research Report: Human ARIH1 (HHARI) Functional Annotation (UniProt Q9Y4X5)

0) Target verification (critical)

The literature retrieved here consistently uses ARIH1 to denote the human RBR-family E3 ligase HHARI, matching UniProt Q9Y4X5 and the described Ariadne/RBR domain organization (RING1–IBR–RING2 plus Ariadne autoinhibitory region). (wang2023theunifyingcatalytic pages 1-2, smit2013ubiquitinchainformation pages 24-26)

1) Key concepts and definitions (current understanding)

1.1 ARIH1 is an RBR (RING-between-RING) E3 ubiquitin ligase

RBR E3 ligases are defined by a RING1–IBR–RING2 module and use a two-step RING/HECT-hybrid catalytic mechanism. In step 1, a ubiquitin-charged E2 binds RING1 and transfers ubiquitin to the E3’s RING2 catalytic cysteine (a transthiolation reaction). In step 2, ubiquitin is transferred from the E3~Ub thioester to a substrate lysine (aminolysis). This general mechanism explicitly includes HHARI/ARIH1 as a canonical member. (wang2023theunifyingcatalytic pages 1-2)

1.2 Core reaction catalyzed and substrate specificity (functional definition)

Reaction (EC 2.3.2.31): transfer of ubiquitin from an E2 conjugating enzyme to substrate proteins via an ARIH1~Ub thioester intermediate. In physiological contexts, the strongest mechanistic evidence supports ARIH1’s role as a CRL-associated “priming” E3, placing an activated ubiquitin transfer module next to substrates bound to neddylated cullin-RING ligases (CRLs)—particularly SCF (CUL1–RBX1–SKP1–F-box) complexes. This geometry is proposed to be especially important for folded/spatially constrained substrates that canonical RING-only mechanisms cannot efficiently ubiquitinate. (hornghetko2021ubiquitinligationto pages 1-2, lin2024diversityofstructure pages 1-3)

1.3 Neddylation and CRL–RBR “E3–E3” cooperation

A major current paradigm is that neddylated CRLs recruit and activate ARIH-family RBR ligases. Neddylation-induced conformational changes in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold handles substrate recruitment and E2 positioning. (hornghetko2021ubiquitinligationto pages 1-2, lin2024diversityofstructure pages 1-3)

2) Molecular mechanism of ARIH1 (what it does and how)

2.1 Autoinhibition and activation

ARIH1/HHARI is autoinhibited by its Ariadne domain and becomes activated through interactions with neddylated cullins/CRLs (and in broader RBR literature, phosphorylation is also described as an activating input for HHARI). (wang2023theunifyingcatalytic pages 1-2, hornghetko2024noncanonicalassemblyneddylation pages 2-3)

2.2 E2 partners (E2-to-E3 handoff)

In the best-defined structural/biochemical pathway (SCF–ARIH1 E3–E3 super-assembly), ubiquitin is transferred from UBE2L3 (UbcH7) to the ARIH1 catalytic cysteine and then to an SCF-bound substrate. (hornghetko2021ubiquitinligationto pages 1-2)

2.3 Structural mechanism: SCF–ARIH1 E3–E3 super-assembly

Horn-Ghetko et al. resolved intermediates by cryo-EM that visualize the sequence: E2~Ub → ARIH1 catalytic cysteine → substrate in the context of a neddylated SCF complex. This provides direct mechanistic support that ARIH1 can function as a catalytic partner of CRLs rather than acting solely as a standalone E3. (hornghetko2021ubiquitinligationto pages 1-2)

Visual evidence supporting this mechanism is shown in the extracted figure panels (transition states and cycle schematic). (hornghetko2021ubiquitinligationto media a3b226ac, hornghetko2021ubiquitinligationto media f3b6a2dc)

2.4 2023 mechanistic consolidation for RBRs (including ARIH1)

A 2023 Nature Communications study synthesized “unifying” RBR features, including the requirement for an open E2~Ub and alignment of the RING2 catalytic cysteine for transthiolation. HHARI/ARIH1 is explicitly included among RBRs whose activation involves interactions with neddylated cullins. (wang2023theunifyingcatalytic pages 1-2)

3) Biological roles, pathways, and cellular localization

3.1 Proteostasis and cell-cycle control via CRL substrates

In the SCF context, ARIH1 supports ubiquitination of substrates presented by F-box proteins (examples include phosphorylated cyclin E and p27), and perturbations stabilize multiple CRL substrates; genome-scale screening evidence places ARIH1 among genes important for cell viability in the same neighborhood as core SCF/neddylation components. (hornghetko2021ubiquitinligationto pages 1-2)

3.2 EMT and cancer progression via hnRNP E1/PCBP1 stability

A mechanistically focused cancer study identified hnRNP E1 (PCBP1) as a direct ARIH1 substrate: ARIH1 promotes K48-linked ubiquitination and proteasomal degradation of hnRNP E1, and mutational analysis highlighted ubiquitinated lysines including K23, K314, K351 with K314R increasing stability and reducing ubiquitination. (howley2022theubiquitine3 pages 1-3, howley2022theubiquitine3 pages 8-9)

Functionally, ARIH1 knockdown delayed EMT and reduced invasion/stemness and tumor outcomes, whereas ARIH1 overexpression promoted EMT/invasion phenotypes; the study reports quantitative elements including 74 enriched ARIH1 proximity interactors and statistically significant in vivo/clinical comparisons (e.g., paired tumor vs metastasis IHC and xenograft endpoints with reported P-values). (howley2022theubiquitine3 pages 8-9, howley2022theubiquitine3 pages 6-8)

3.3 Translation control connections (context and evidence base)

ARIH1 has been linked to translation control contexts (including DNA damage–related translation arrest) in the cancer-focused ARIH1 study, and ARIH1/HHARI has been discussed in the 4EHP/eIF4E2 literature as associating with 4EHP under specific cellular conditions. However, in the retrieved evidence set, the most direct substrate-level and phenotype-level support is for hnRNP E1 and CRL/SCF substrates rather than for a single definitive translation-factor substrate. (howley2022theubiquitine3 pages 1-3, smit2013ubiquitinchainformation pages 26-29)

3.4 Innate immune signaling (emerging/less mature evidence)

A recent preprint reports HHARI/ARIH1 as an activator of RIG-I–mediated type I interferon signaling in a neddylation-dependent manner. It reports that the RING2 catalytic cysteine mutant (C357A) abolishes the phenotype, that HHARI physically interacts with RIG-I, and that inhibiting neddylation (NAE inhibitor MLN4924) suppresses HHARI-driven responses (including IFNβ secretion and downstream signaling readouts). This supports a model where HHARI’s regulation by neddylated CRLs can be functionally coupled to antiviral signaling. Because this is a preprint, it should be treated as emerging rather than fully consolidated. (kontra2025theacidicnterminus pages 33-35, kontra2025theacidicnterminus pages 9-12)

3.5 Subcellular localization

In tumor/pathology and cell-based studies, ARIH1 was detected in both cytoplasm and nucleus by staining, consistent with a role in diverse protein quality control and regulatory circuits. In the core mechanistic work, ARIH1 localizes functionally through complex formation with neddylated CRL assemblies (e.g., SCF). (howley2022theubiquitine3 pages 6-8, hornghetko2021ubiquitinligationto pages 1-2)

4) Recent developments (prioritize 2023–2024)

4.1 2024: refined view of CRL geometry and catalytic partnering

A 2024 Current Opinion in Structural Biology review highlights ARIH1/ARIH2 as CRL-associated RBR ligases that can perform priming ubiquitination and emphasizes that neddylation can strongly accelerate CRL reactions (including an example of ~2000-fold acceleration for a UBE2D-mediated reaction in the CRL context). It also articulates a functional division where ARIH1 is favored for substrates that are geometrically hard to reach for the E2 in a RING-only mechanism. (lin2024diversityofstructure pages 3-5)

4.2 2024: broader cullin–RBR chimeric assemblies

A 2024 Nature Structural & Molecular Biology study on the vertebrate-specific CUL9 complex discusses ARIH-family RBR catalytic principles and emphasizes ARIH1-like autoinhibition/activation logic involving neddylated cullins and RBX RING interactions, underscoring that cullin–RBR cooperation is a recurring design in the ubiquitin system. (hornghetko2024noncanonicalassemblyneddylation pages 2-3)

4.3 2023: mechanistic unification of the RBR family including HHARI

The 2023 Nature Communications paper consolidated structural/biochemical principles underlying RBR catalysis, explicitly positioning HHARI/ARIH1 as part of an RBR family that uses a conserved transthiolation-centered catalytic cycle and can be activated in the context of neddylated cullins. (wang2023theunifyingcatalytic pages 1-2)

5) Current applications and real-world implementations

5.1 Targeted protein degradation (TPD) and PROTAC ecosystem (ARIH1-adjacent)

While ARIH1 itself is not yet a common recruited ligase in marketed degraders, its core partner system—cullin-RING ligases—is central to real-world TPD. The 2024 structural review notes that CRL2\u1d5bVHL is a commonly used E3 ligase scaffold in PROTAC designs, highlighting the clinical/biotech relevance of CRLs. Because ARIH1 can act as a CRL catalytic partner for certain substrates, mechanistic understanding of ARIH1 expands the design space for how CRL-based ubiquitination can be engineered or inhibited. (lin2024diversityofstructure pages 3-5)

5.2 Neddylation as a pharmacologic lever (relevant to ARIH1 activation)

Because ARIH1 activation in multiple contexts depends on neddylated CRLs, neddylation is an actionable upstream node. In immune signaling experiments, neddylation inhibition with MLN4924 suppressed HHARI/ARIH1-dependent phenotypes (preprint evidence). Conceptually, this points to neddylation as a potential therapeutic control point for processes where ARIH1 cooperates with CRLs, including CRL-driven proteostasis/cell-cycle and possibly innate immune signaling. (kontra2025theacidicnterminus pages 33-35)

5.3 Disease-oriented implementation: cancer progression mechanisms

ARIH1’s role in EMT and metastasis-like phenotypes (via hnRNP E1 stability control) positions it as a mechanistically grounded node for biomarker development or pathway intervention in oncology research settings. (howley2022theubiquitine3 pages 6-8, howley2022theubiquitine3 pages 1-3)

6) Expert synthesis and analysis (what authoritative sources imply)

6.1 Primary function (most strongly supported)

The strongest convergent evidence supports ARIH1 as a catalytic RBR E3 that cooperates with neddylated CRLs to enable ubiquitination of otherwise geometrically challenging substrates—acting as a “catalytic extender/primer” of CRL ubiquitination capacity rather than merely a standalone ligase. (hornghetko2021ubiquitinligationto pages 1-2, lin2024diversityofstructure pages 1-3)

6.2 Where the field is still uncertain

Substrate scope: Beyond SCF-presented substrates and hnRNP E1, ARIH1 substrate identification remains incomplete; reviews emphasize context dependence (substrate geometry, cullin identity, E2 choice). (lin2024diversityofstructure pages 1-3)

Innate immunity: HHARI/ARIH1–RIG-I signaling is supported by mechanistic perturbation in a preprint but awaits broader replication and peer-reviewed consolidation. (kontra2025theacidicnterminus pages 33-35)

6.3 Constraint/essentiality

Multiple lines of evidence are consistent with ARIH1 being fitness-relevant/essential: it appears as essential in cell-viability CRISPR screens in mechanistic work, and human population constraint commentary notes predicted loss-of-function variants are rare (preprint). (hornghetko2021ubiquitinligationto pages 1-2, kontra2025theacidicnterminus pages 9-12)

7) Relevant recent statistics and quantitative data (from available sources)

Human E3 ligase repertoire: >600 E3 ligases cited in a 2023 review, providing scale/context for ARIH1 within the UPS. (jeong2023targetinge3ubiquitin pages 1-2)
NEDD8 impact on CRL catalysis: a 2024 structural review reports neddylation can accelerate a UBE2D-mediated CRL reaction by ~2000-fold (context for why neddylation-dependent ARIH activation is biologically potent). (lin2024diversityofstructure pages 3-5)
ARIH1 interactome size in a focused cancer study: 74 enriched ARIH1 interactors via miniTurboID proximity labeling/MS. (howley2022theubiquitine3 pages 8-9)
Quantitative/statistical phenotypes in cancer models: reported significant differences across IHC comparisons (paired tests) and in vivo tumor/colonization outcomes with reported P-values and group sizes in the ARIH1–hnRNP E1 study. (howley2022theubiquitine3 pages 6-8)
Innate immune signaling readouts (emerging): IFNβ ELISA plots show outputs scaled up to approximately 6,000 pg/mL and suppression by MLN4924 10 μM in HHARI-driven assays (preprint). (kontra2025theacidicnterminus pages 36-36, kontra2025theacidicnterminus pages 33-35)

8) Database-level disease associations (hypothesis-generating)

Open Targets lists ARIH1 associations (varying strength and evidence counts) with broad disease categories including neoplasm, aortic aneurysm, thoracic aortic aneurysm, and neurodegenerative disease. These should be used as starting points for targeted literature review rather than as definitive causal claims. (OpenTargets Search: -ARIH1)

Summary table

The following table consolidates ARIH1’s identity, mechanism, regulation, substrates, roles, and recent developments (with URLs and publication dates).

Functional aspect	Specific details	Key evidence type	Primary supporting citations	Source URL + publication date
Identity / verified target	Human ARIH1 encodes HHARI (also called Ariadne RBR E3 ubiquitin protein ligase 1), an RBR-family E3 ligase with RING1–IBR–RING2 catalytic core plus an Ariadne autoinhibitory region; this matches UniProt Q9Y4X5 and the Ariadne subfamily annotation.	Structural/mechanistic paper; review	(wang2023theunifyingcatalytic pages 1-2, smit2013ubiquitinchainformation pages 24-26)	Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z; Smit (2013, thesis/review-style source)
Domain architecture	RING1 recruits E2~Ub, IBR links the RBR scaffold, and RING2 contains the catalytic cysteine for transthiolation; the Ariadne domain restrains the catalytic module in an autoinhibited state until activation.	Structural biology; biochemical mechanism	(wang2023theunifyingcatalytic pages 1-2, hornghetko2024noncanonicalassemblyneddylation pages 2-3)	Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z; Horn-Ghetko et al., Nat Struct Mol Biol (2024-04), https://doi.org/10.1038/s41594-024-01257-y
Catalytic mechanism	ARIH1 uses the canonical RBR two-step mechanism: ubiquitin is transferred from an E2 to the RING2 catalytic cysteine of ARIH1 by transthiolation, then from ARIH1 to substrate by aminolysis.	Cryo-EM; biochemistry; mechanistic review	(wang2023theunifyingcatalytic pages 1-2, hornghetko2021ubiquitinligationto pages 1-2)	Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z; Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9
Activation by neddylated CRLs	A key current model is that neddylated cullin-RING ligases (CRLs) activate ARIH1 by relieving autoinhibition and positioning ARIH1 for substrate ubiquitination. ARIH1 cooperates especially with RBX1-containing CUL1/CUL2/CUL3 complexes.	Cryo-EM; structural/mechanistic review	(hornghetko2024noncanonicalassemblyneddylation pages 2-3, wang2023theunifyingcatalytic pages 1-2, lin2024diversityofstructure pages 1-3)	Horn-Ghetko et al., Nat Struct Mol Biol (2024-04), https://doi.org/10.1038/s41594-024-01257-y; Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z; Lin & Komives, Curr Opin Struct Biol (2024-10), https://doi.org/10.1016/j.sbi.2024.102879
E3–E3 super-assembly with SCF ligases	In a landmark model, neddylated SCF (CUL1–RBX1–SKP1–F-box) complexes and ARIH1 form an E3–E3 super-assembly. Cryo-EM visualized transfer from UBE2L3 to the ARIH1 catalytic cysteine and then to SCF-bound substrate, explaining how CRLs ubiquitinate geometrically difficult substrates.	Cryo-EM; chemical probes; biochemistry	(hornghetko2021ubiquitinligationto pages 1-2, hornghetko2021ubiquitinligationto media a3b226ac, hornghetko2021ubiquitinligationto media f3b6a2dc)	Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9
E2 partners	ARIH1 is most strongly linked to UBE2L3/UbcH7 as the donor E2 in the SCF–ARIH1 pathway; broader RBR work also uses UbcH5B/UBE2D-family conjugates to interrogate RBR catalysis, and older literature reported interaction with UBE2L3 and UBE2L6.	Cryo-EM; ITC/biochemistry; older interaction literature	(hornghetko2021ubiquitinligationto pages 1-2, wang2023theunifyingcatalytic pages 1-2, smit2013ubiquitinchainformation pages 26-29, kontra2025theacidicnterminus pages 37-37)	Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9; Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z
Substrate class specificity	ARIH1 appears particularly important for folded or spatially constrained CRL substrates that a canonical RING E2 cannot easily reach; by contrast, some extended or disordered substrates can be ubiquitinated without ARIH1.	Mechanistic study; structural review	(hornghetko2021ubiquitinligationto pages 1-2, lin2024diversityofstructure pages 1-3)	Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9; Lin & Komives, Curr Opin Struct Biol (2024-10), https://doi.org/10.1016/j.sbi.2024.102879
Representative CRL-linked substrates	In the SCF context, ARIH1 contributes to ubiquitination of substrates such as phosphorylated cyclin E and p27, and ARIH1 knockdown stabilizes multiple CRL substrates.	Cryo-EM; biochemical and cellular perturbation	(hornghetko2021ubiquitinligationto pages 1-2)	Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9
Direct substrate: hnRNP E1 (PCBP1)	hnRNP E1 is a validated ARIH1 substrate in breast cancer models. ARIH1 promotes K48-linked ubiquitination and proteasomal degradation; ubiquitinated lysines include K23, K314, K351, with K314R increasing stability and reducing ubiquitination.	Yeast 2-hybrid; miniTurboID proteomics; CHX chase; IP/immunoblot; mutagenesis	(howley2022theubiquitine3 pages 8-9, howley2022theubiquitine3 pages 1-3)	Howley et al., Oncogene (2022-01), https://doi.org/10.1038/s41388-022-02199-9
Putative or previous substrate links	Earlier literature associated HHARI/ARIH1 with 4EHP/eIF4E2 and with degradation of synphilin-1 and SIM2 in cells, but these links are less central and generally less definitive than the CRL-priming and hnRNP E1 data.	Earlier cell-based studies; review	(smit2013ubiquitinchainformation pages 26-29)	Smit (2013, thesis/review-style source)
Translation control / proteostasis	Reviews of 4EHP/eIF4E2 note that under stress or DNA-damage contexts HHARI/ARIH1 accumulates and associates with 4EHP, linking ARIH1 to translational repression pathways; ARIH1 has also been implicated in DNA damage-induced translational arrest in cancer cells.	Review; prior cell biology	(howley2022theubiquitine3 pages 8-9)	Christie & Igreja, FEBS J (2023-11), https://doi.org/10.1111/febs.16275; Howley et al., Oncogene (2022-01), https://doi.org/10.1038/s41388-022-02199-9
EMT / cancer progression	ARIH1 promotes EMT, invasion, stemness, and tumor progression in breast cancer models; ARIH1 knockdown delays EMT, reduces invasion, and lowers tumor formation, while overexpression has the opposite effect.	Cell assays; xenografts; IHC; proteomics	(howley2022theubiquitine3 pages 1-3, howley2022theubiquitine3 pages 6-8)	Howley et al., Oncogene (2022-01), https://doi.org/10.1038/s41388-022-02199-9
Quantitative cancer-related findings	MiniTurboID proximity labeling identified 74 enriched ARIH1 interactors; metastasis IHC analyses in matched samples reported significant ARIH1 elevation (paired t-test P<0.05), and xenograft or lung-colonization effects included significant differences (for example, two-way ANOVA with Bonferroni, P<0.001 in reported experiments).	Quantitative proteomics; pathology; in vivo assays	(howley2022theubiquitine3 pages 8-9, howley2022theubiquitine3 pages 6-8)	Howley et al., Oncogene (2022-01), https://doi.org/10.1038/s41388-022-02199-9
Innate immunity / RIG-I signaling	Recent work links HHARI/ARIH1 to RIG-I-mediated type I interferon signaling. Catalytic activity is required (C357A inactive), the acidic N-terminus is important, HHARI can interact with RIG-I, and responses are strongly neddylation-dependent.	Preprint; cell signaling assays; co-IP; ELISA; microscopy	(kontra2025theacidicnterminus pages 9-12, kontra2025theacidicnterminus pages 33-35, kontra2025theacidicnterminus pages 36-37)	Kontra et al., bioRxiv (2025-02), https://doi.org/10.1101/2025.02.01.636034
Quantitative immune findings	In interferon assays, HHARI increased IFNβ secretion with readouts scaled up to about 6,000 pg/mL in figures; MLN4924 (10 μM) suppressed HHARI-dependent signaling, and 30 nM siRNA against DDX58/RIG-I or MAVS reduced HHARI-driven responses.	ELISA; inhibitor studies; siRNA perturbation	(kontra2025theacidicnterminus pages 36-36, kontra2025theacidicnterminus pages 33-35, kontra2025theacidicnterminus pages 36-37)	Kontra et al., bioRxiv (2025-02), https://doi.org/10.1101/2025.02.01.636034
Localization	ARIH1 is primarily an intracellular ligase acting in the cytoplasm and nucleus; tumor studies detected ARIH1 staining in both compartments, and functionally ARIH1 operates in multiprotein complexes with CRLs, RNA-binding factors, and signaling proteins.	IHC/cell biology; structural complex data	(howley2022theubiquitine3 pages 6-8, hornghetko2021ubiquitinligationto pages 1-2)	Howley et al., Oncogene (2022-01), https://doi.org/10.1038/s41388-022-02199-9; Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9
Essentiality / constraint	ARIH1 behaves like an essential or fitness-relevant UPS component in several datasets: genome-wide CRISPR screens identified ARIH1 as important for cell viability, and gnomAD-based commentary notes that predicted human loss-of-function variants are very rare.	CRISPR screens; population genetics commentary	(hornghetko2021ubiquitinligationto pages 1-2, kontra2025theacidicnterminus pages 9-12)	Horn-Ghetko et al., Nature (2021-02), https://doi.org/10.1038/s41586-021-03197-9; Kontra et al., bioRxiv (2025-02), https://doi.org/10.1101/2025.02.01.636034
Disease links / database-level associations	Open Targets lists low-to-moderate evidence links between ARIH1 and neoplasm, aortic aneurysm, thoracic aortic aneurysm, neurodegenerative disease, and abruptio placentae; these are hypothesis-generating rather than definitive functional assignments.	Database aggregation	(OpenTargets Search: -ARIH1)	Open Targets Platform query for ARIH1 (accessed via tool context; no publication date provided)
Key 2023 development	The 2023 mechanistic synthesis strengthened the view that HHARI/ARIH1 conforms to a unifying RBR catalytic mechanism, emphasizing the open E2~Ub conformation and allosteric activation features shared across RBR ligases.	High-impact mechanistic paper	(wang2023theunifyingcatalytic pages 1-2)	Wang et al., Nat Commun (2023-01), https://doi.org/10.1038/s41467-023-35871-z
Key 2024 developments	2024 studies and reviews extended ARIH1 functional annotation by framing it as a geometrically optimized catalytic partner for CRLs and by generalizing ARIH-type cooperation across cullin ligase systems, including noncanonical cullin–RBR assemblies.	Structural review; primary structural paper	(hornghetko2024noncanonicalassemblyneddylation pages 2-3, lin2024diversityofstructure pages 1-3)	Horn-Ghetko et al., Nat Struct Mol Biol (2024-04), https://doi.org/10.1038/s41594-024-01257-y; Lin & Komives, Curr Opin Struct Biol (2024-10), https://doi.org/10.1016/j.sbi.2024.102879

Table: This table summarizes verified identity, catalytic mechanism, activation, substrate biology, pathway roles, localization, and recent developments for human ARIH1/HHARI. It prioritizes 2023–2024 sources while retaining the key 2021 and 2022 primary papers that established major mechanistic and disease-relevant functions.

Key visual evidence

Cryo-EM intermediates and cycle schematics supporting the SCF–ARIH1 E3–E3 ubiquitination mechanism (E2~Ub → ARIH1 catalytic cysteine → substrate) are shown in extracted panels. (hornghetko2021ubiquitinligationto media a3b226ac, hornghetko2021ubiquitinligationto media f3b6a2dc)

References

(wang2023theunifyingcatalytic pages 1-2): Xiangyi S. Wang, Thomas R. Cotton, Sarah J. Trevelyan, Lachlan W. Richardson, Wei Ting Lee, John Silke, and Bernhard C. Lechtenberg. The unifying catalytic mechanism of the ring-between-ring e3 ubiquitin ligase family. Nature Communications, Jan 2023. URL: https://doi.org/10.1038/s41467-023-35871-z, doi:10.1038/s41467-023-35871-z. This article has 65 citations and is from a highest quality peer-reviewed journal.
(smit2013ubiquitinchainformation pages 24-26): J Smit. Ubiquitin chain formation by rbr e3-ligases. Unknown journal, 2013.
(hornghetko2021ubiquitinligationto pages 1-2): Daniel Horn-Ghetko, David T. Krist, J. Rajan Prabu, Kheewoong Baek, Monique P. C. Mulder, Maren Klügel, Daniel C. Scott, Huib Ovaa, Gary Kleiger, and Brenda A. Schulman. Ubiquitin ligation to f-box protein targets by scf–rbr e3–e3 super-assembly. Nature, 590:671-676, Feb 2021. URL: https://doi.org/10.1038/s41586-021-03197-9, doi:10.1038/s41586-021-03197-9. This article has 199 citations and is from a highest quality peer-reviewed journal.
(lin2024diversityofstructure pages 1-3): Calvin P. Lin and Elizabeth A. Komives. Diversity of structure and function in cullin e3 ligases. Current Opinion in Structural Biology, 88:102879, Oct 2024. URL: https://doi.org/10.1016/j.sbi.2024.102879, doi:10.1016/j.sbi.2024.102879. This article has 14 citations and is from a peer-reviewed journal.
(hornghetko2024noncanonicalassemblyneddylation pages 2-3): Daniel Horn-Ghetko, Linus V. M. Hopf, Ishita Tripathi-Giesgen, Jiale Du, Sebastian Kostrhon, D. Tung Vu, Viola Beier, Barbara Steigenberger, J. Rajan Prabu, Luca Stier, Elias M. Bruss, Matthias Mann, Yue Xiong, and Brenda A. Schulman. Noncanonical assembly, neddylation and chimeric cullin–ring/rbr ubiquitylation by the 1.8 mda cul9 e3 ligase complex. Nature Structural & Molecular Biology, 31:1083-1094, Apr 2024. URL: https://doi.org/10.1038/s41594-024-01257-y, doi:10.1038/s41594-024-01257-y. This article has 13 citations and is from a highest quality peer-reviewed journal.
(hornghetko2021ubiquitinligationto media a3b226ac): Daniel Horn-Ghetko, David T. Krist, J. Rajan Prabu, Kheewoong Baek, Monique P. C. Mulder, Maren Klügel, Daniel C. Scott, Huib Ovaa, Gary Kleiger, and Brenda A. Schulman. Ubiquitin ligation to f-box protein targets by scf–rbr e3–e3 super-assembly. Nature, 590:671-676, Feb 2021. URL: https://doi.org/10.1038/s41586-021-03197-9, doi:10.1038/s41586-021-03197-9. This article has 199 citations and is from a highest quality peer-reviewed journal.
(hornghetko2021ubiquitinligationto media f3b6a2dc): Daniel Horn-Ghetko, David T. Krist, J. Rajan Prabu, Kheewoong Baek, Monique P. C. Mulder, Maren Klügel, Daniel C. Scott, Huib Ovaa, Gary Kleiger, and Brenda A. Schulman. Ubiquitin ligation to f-box protein targets by scf–rbr e3–e3 super-assembly. Nature, 590:671-676, Feb 2021. URL: https://doi.org/10.1038/s41586-021-03197-9, doi:10.1038/s41586-021-03197-9. This article has 199 citations and is from a highest quality peer-reviewed journal.
(howley2022theubiquitine3 pages 1-3): Breege V. Howley, Bidyut Mohanty, Annamarie Dalton, Simon Grelet, Joseph Karam, Toros Dincman, and Philip H. Howe. The ubiquitin e3 ligase arih1 regulates hnrnp e1 protein stability, emt and breast cancer progression. Oncogene, 41:1679-1690, Jan 2022. URL: https://doi.org/10.1038/s41388-022-02199-9, doi:10.1038/s41388-022-02199-9. This article has 40 citations and is from a domain leading peer-reviewed journal.
(howley2022theubiquitine3 pages 8-9): Breege V. Howley, Bidyut Mohanty, Annamarie Dalton, Simon Grelet, Joseph Karam, Toros Dincman, and Philip H. Howe. The ubiquitin e3 ligase arih1 regulates hnrnp e1 protein stability, emt and breast cancer progression. Oncogene, 41:1679-1690, Jan 2022. URL: https://doi.org/10.1038/s41388-022-02199-9, doi:10.1038/s41388-022-02199-9. This article has 40 citations and is from a domain leading peer-reviewed journal.
(howley2022theubiquitine3 pages 6-8): Breege V. Howley, Bidyut Mohanty, Annamarie Dalton, Simon Grelet, Joseph Karam, Toros Dincman, and Philip H. Howe. The ubiquitin e3 ligase arih1 regulates hnrnp e1 protein stability, emt and breast cancer progression. Oncogene, 41:1679-1690, Jan 2022. URL: https://doi.org/10.1038/s41388-022-02199-9, doi:10.1038/s41388-022-02199-9. This article has 40 citations and is from a domain leading peer-reviewed journal.
(smit2013ubiquitinchainformation pages 26-29): J Smit. Ubiquitin chain formation by rbr e3-ligases. Unknown journal, 2013.
(kontra2025theacidicnterminus pages 33-35): Ioanna Kontra, Harry Ward, Faith Vinluan, Rachel Lau, Vinothini Rajeeve, Pedro Cutillas, Benjamin Stieglitz, and Myles J. Lewis. The acidic n-terminus of hhari and neddylation are essential for the activation and maintenance of rig-i-mediated type i interferon response. bioRxiv, Feb 2025. URL: https://doi.org/10.1101/2025.02.01.636034, doi:10.1101/2025.02.01.636034. This article has 0 citations.
(kontra2025theacidicnterminus pages 9-12): Ioanna Kontra, Harry Ward, Faith Vinluan, Rachel Lau, Vinothini Rajeeve, Pedro Cutillas, Benjamin Stieglitz, and Myles J. Lewis. The acidic n-terminus of hhari and neddylation are essential for the activation and maintenance of rig-i-mediated type i interferon response. bioRxiv, Feb 2025. URL: https://doi.org/10.1101/2025.02.01.636034, doi:10.1101/2025.02.01.636034. This article has 0 citations.
(lin2024diversityofstructure pages 3-5): Calvin P. Lin and Elizabeth A. Komives. Diversity of structure and function in cullin e3 ligases. Current Opinion in Structural Biology, 88:102879, Oct 2024. URL: https://doi.org/10.1016/j.sbi.2024.102879, doi:10.1016/j.sbi.2024.102879. This article has 14 citations and is from a peer-reviewed journal.
(jeong2023targetinge3ubiquitin pages 1-2): Yelin Jeong, Ah-Reum Oh, Young Hoon Jung, HyunJoon Gi, Young Un Kim, and KyeongJin Kim. Targeting e3 ubiquitin ligases and their adaptors as a therapeutic strategy for metabolic diseases. Experimental & Molecular Medicine, 55:2097-2104, Oct 2023. URL: https://doi.org/10.1038/s12276-023-01087-w, doi:10.1038/s12276-023-01087-w. This article has 56 citations and is from a peer-reviewed journal.
(kontra2025theacidicnterminus pages 36-36): Ioanna Kontra, Harry Ward, Faith Vinluan, Rachel Lau, Vinothini Rajeeve, Pedro Cutillas, Benjamin Stieglitz, and Myles J. Lewis. The acidic n-terminus of hhari and neddylation are essential for the activation and maintenance of rig-i-mediated type i interferon response. bioRxiv, Feb 2025. URL: https://doi.org/10.1101/2025.02.01.636034, doi:10.1101/2025.02.01.636034. This article has 0 citations.
(OpenTargets Search: -ARIH1): Open Targets Query (-ARIH1, 5 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
(kontra2025theacidicnterminus pages 37-37): Ioanna Kontra, Harry Ward, Faith Vinluan, Rachel Lau, Vinothini Rajeeve, Pedro Cutillas, Benjamin Stieglitz, and Myles J. Lewis. The acidic n-terminus of hhari and neddylation are essential for the activation and maintenance of rig-i-mediated type i interferon response. bioRxiv, Feb 2025. URL: https://doi.org/10.1101/2025.02.01.636034, doi:10.1101/2025.02.01.636034. This article has 0 citations.
(kontra2025theacidicnterminus pages 36-37): Ioanna Kontra, Harry Ward, Faith Vinluan, Rachel Lau, Vinothini Rajeeve, Pedro Cutillas, Benjamin Stieglitz, and Myles J. Lewis. The acidic n-terminus of hhari and neddylation are essential for the activation and maintenance of rig-i-mediated type i interferon response. bioRxiv, Feb 2025. URL: https://doi.org/10.1101/2025.02.01.636034, doi:10.1101/2025.02.01.636034. This article has 0 citations.

Citations

wang2023theunifyingcatalytic pages 1-2
hornghetko2021ubiquitinligationto pages 1-2
lin2024diversityofstructure pages 3-5
hornghetko2024noncanonicalassemblyneddylation pages 2-3
kontra2025theacidicnterminus pages 33-35
lin2024diversityofstructure pages 1-3
smit2013ubiquitinchainformation pages 26-29
smit2013ubiquitinchainformation pages 24-26
kontra2025theacidicnterminus pages 9-12
kontra2025theacidicnterminus pages 36-36
kontra2025theacidicnterminus pages 37-37
kontra2025theacidicnterminus pages 36-37
https://doi.org/10.1038/s41467-023-35871-z;
https://doi.org/10.1038/s41594-024-01257-y
https://doi.org/10.1038/s41586-021-03197-9
https://doi.org/10.1038/s41594-024-01257-y;
https://doi.org/10.1016/j.sbi.2024.102879
https://doi.org/10.1038/s41586-021-03197-9;
https://doi.org/10.1038/s41467-023-35871-z
https://doi.org/10.1038/s41388-022-02199-9
https://doi.org/10.1111/febs.16275;
https://doi.org/10.1101/2025.02.01.636034
https://doi.org/10.1038/s41388-022-02199-9;
https://doi.org/10.1038/s41467-023-35871-z,
https://doi.org/10.1038/s41586-021-03197-9,
https://doi.org/10.1016/j.sbi.2024.102879,
https://doi.org/10.1038/s41594-024-01257-y,
https://doi.org/10.1038/s41388-022-02199-9,
https://doi.org/10.1101/2025.02.01.636034,
https://doi.org/10.1038/s12276-023-01087-w,

📄 View Raw YAML

id: Q9Y4X5
gene_symbol: ARIH1
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: 'ARIH1 encodes HHARI, an intracellular Ariadne/RBR E3 ubiquitin ligase that catalyzes
  ubiquitin transfer through a RING1-IBR-RING2 mechanism and is activated by neddylated cullin-RING
  ligase complexes, especially SCF assemblies, to prime ubiquitination of constrained CRL
  substrates.'
existing_annotations:
  - term:
      id: GO:0005737
      label: cytoplasm
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: cytoplasm localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0031624
      label: ubiquitin conjugating enzyme binding
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR
        catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0006511
      label: ubiquitin-dependent protein catabolic process
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: ubiquitin-dependent protein catabolic process is supported by the
        catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent
        substrate turnover, especially as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0061630
      label: ubiquitin protein ligase activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: 'ubiquitin protein ligase activity is a core ARIH1 function: ARIH1/HHARI is
        an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0000151
      label: ubiquitin ligase complex
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: ARIH1 forms functional ubiquitin ligase assemblies with neddylated CRLs;
        this broad complex annotation captures that E3-ligase-complex context.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005634
      label: nucleus
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: nucleus localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000002
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0005634
      label: nucleus
    evidence_type: IEA
    original_reference_id: GO_REF:0000044
    review:
      summary: nucleus localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005737
      label: cytoplasm
    evidence_type: IEA
    original_reference_id: GO_REF:0000044
    review:
      summary: cytoplasm localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0008270
      label: zinc ion binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000002
    review:
      summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3
        mechanism, so zinc ion binding is supported.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0015030
      label: Cajal body
    evidence_type: IEA
    original_reference_id: GO_REF:0000044
    review:
      summary: Cajal body is retained as a reported localization or colocalization but
        is not part of the core ARIH1 ubiquitin-ligase mechanism.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Nucleus, Cajal body
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Present in Lewy body
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0046872
      label: metal ion binding
    evidence_type: IEA
    original_reference_id: GO_REF:0000002
    review:
      summary: The metal-binding evidence is specifically zinc binding by RING/IBR/RING
        domains; the broad metal ion binding term should be replaced by zinc ion
        binding.
      action: MODIFY
      reason: Specific zinc-binding domains are known; the generic metal ion binding
        term is less informative.
      proposed_replacement_terms:
        - id: GO:0008270
          label: zinc ion binding
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0061630
      label: ubiquitin protein ligase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000003
    review:
      summary: 'ubiquitin protein ligase activity is a core ARIH1 function: ARIH1/HHARI is
        an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:21145461
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:21532592
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:23707686
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:24076655
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:28514442
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:33961781
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005654
      label: nucleoplasm
    evidence_type: IDA
    original_reference_id: GO_REF:0000052
    review:
      summary: nucleoplasm localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0039585
      label: PKR/eIFalpha signaling
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9833482
    review:
      summary: PKR/eIFalpha signaling is a pathway-level consequence in Reactome rather
        than the core molecular role of ARIH1; keep it as non-core while prioritizing
        ubiquitin/ubiquitin-like ligase activity.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169394
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169395
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169398
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169402
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169405
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169406
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0061662
      label: ISG15 ligase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9833973
    review:
      summary: 'ISG15 ligase activity is retained as a confirmed secondary ubiquitin-like/ISGylation
        function: UniProt explicitly states that ARIH1 acts as the ligase involved in ISGylation
        of EIF4E2, while the dominant core function remains ubiquitin transfer with neddylated
        CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:23707686
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:27565346
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0005737
      label: cytoplasm
    evidence_type: IDA
    original_reference_id: PMID:23059369
    review:
      summary: cytoplasm localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0008270
      label: zinc ion binding
    evidence_type: IDA
    original_reference_id: PMID:23707686
    review:
      summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3
        mechanism, so zinc ion binding is supported.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:23707686
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:27565346
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0016604
      label: nuclear body
    evidence_type: IDA
    original_reference_id: PMID:23059369
    review:
      summary: nuclear body is retained as a reported localization or colocalization but
        is not part of the core ARIH1 ubiquitin-ligase mechanism.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Nucleus, Cajal body
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Present in Lewy body
  - term:
      id: GO:0019005
      label: SCF ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: 'SCF ubiquitin ligase complex association is part of the best-supported ARIH1
        mechanism: ARIH1 cooperates with neddylated SCF complexes as a catalytic E3-E3 super-assembly
        for CRL substrate ubiquitination.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0019005
      label: SCF ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:27565346
    review:
      summary: 'SCF ubiquitin ligase complex association is part of the best-supported ARIH1
        mechanism: ARIH1 cooperates with neddylated SCF complexes as a catalytic E3-E3 super-assembly
        for CRL substrate ubiquitination.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0031462
      label: Cul2-RING ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:27565346
    negated: true
    review:
      summary: This NOT-qualified Cul2-RING complex annotation is retained as a
        non-core, experiment-specific negative result from PMID:27565346, but it
        conflicts with positive CUL2 interaction evidence from PMID:24076655 and with
        UniProt text citing both PMID:24076655 and PMID:27565346 for neddylated CUL2
        interaction. The most defensible interpretation is context-dependent assay
        behavior rather than a global absence of CUL2 association.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
      reason: Preserve the GOA NOT qualifier while explicitly flagging the conflict with
        broader positive CUL2 evidence.
  - term:
      id: GO:0031462
      label: Cul2-RING ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: Positive Cul2-RING complex association is retained as a non-core CRL
        context for ARIH1. This should be read alongside the separate NOT-qualified
        PMID:27565346 annotation, which likely reflects a context-specific negative
        assay rather than a global absence of CUL2 interaction.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
      reason: ARIH1-CRL cooperation is well supported, but individual cullin-complex
        annotations are context annotations rather than the core catalytic function.
  - term:
      id: GO:0031463
      label: Cul3-RING ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: Cul3-RING ubiquitin ligase complex association is supported as a CRL
        partnership for ARIH1; it is retained as a non-core complex context rather than
        the core catalytic activity itself.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0031463
      label: Cul3-RING ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:27565346
    review:
      summary: Cul3-RING ubiquitin ligase complex association is supported as a CRL
        partnership for ARIH1; it is retained as a non-core complex context rather than
        the core catalytic activity itself.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0031464
      label: Cul4A-RING E3 ubiquitin ligase complex
    evidence_type: IDA
    original_reference_id: PMID:24076655
    review:
      summary: Cul4A-RING E3 ubiquitin ligase complex association is supported as a CRL
        partnership for ARIH1; it is retained as a non-core complex context rather than
        the core catalytic activity itself.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0031624
      label: ubiquitin conjugating enzyme binding
    evidence_type: IPI
    original_reference_id: PMID:23707686
    review:
      summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR
        catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0031624
      label: ubiquitin conjugating enzyme binding
    evidence_type: IPI
    original_reference_id: PMID:24076655
    review:
      summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR
        catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0031624
      label: ubiquitin conjugating enzyme binding
    evidence_type: IPI
    original_reference_id: PMID:27565346
    review:
      summary: ARIH1 binding to ubiquitin-conjugating enzymes is part of its core RBR
        catalytic cycle, with UBE2L3/UbcH7 the best-supported donor E2.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0097413
      label: Lewy body
    evidence_type: IDA
    original_reference_id: PMID:21590270
    review:
      summary: Lewy body is retained as a reported localization or colocalization but is
        not part of the core ARIH1 ubiquitin-ligase mechanism.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Nucleus, Cajal body
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Present in Lewy body
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169394
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169395
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169398
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169402
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169403
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169405
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1169406
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1678843
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9833973
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9837231
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0005829
      label: cytosol
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-9927247
    review:
      summary: cytosol localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:14623119
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:15236971
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0004842
      label: ubiquitin-protein transferase activity
    evidence_type: IDA
    original_reference_id: PMID:21532592
    review:
      summary: 'ubiquitin-protein transferase activity is a core ARIH1 function: ARIH1/HHARI
        is an RBR E3 that transfers ubiquitin from an E2 enzyme through its catalytic cysteine
        to substrates.'
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: RBR E3 ligases are defined by a **RING1–IBR–RING2** module
            and use a **two-step** RING/HECT-hybrid catalytic mechanism. In step 1, a
            ubiquitin-charged E2 binds **RING1** and transfers ubiquitin to the E3’s
            **RING2 catalytic cysteine** (a **transthiolation** reaction). In step 2,
            ubiquitin is transferred from the E3~Ub thioester to a substrate lysine
            (aminolysis). This general mechanism explicitly includes **HHARI/ARIH1** as
            a canonical member.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:14623119
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0005737
      label: cytoplasm
    evidence_type: IDA
    original_reference_id: PMID:11278816
    review:
      summary: cytoplasm localization is supported for intracellular ARIH1; the most
        relevant functional locations are cytoplasm/cytosol and nucleus.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In tumor/pathology and cell-based studies, ARIH1 was detected
            in both **cytoplasm and nucleus** by staining, consistent with a role in
            diverse protein quality control and regulatory circuits. In the core
            mechanistic work, ARIH1 localizes functionally through **complex formation**
            with neddylated CRL assemblies (e.g., SCF).
  - term:
      id: GO:0008270
      label: zinc ion binding
    evidence_type: IDA
    original_reference_id: PMID:15236971
    review:
      summary: ARIH1 contains RING/IBR/RING zinc-finger domains required for its RBR E3
        mechanism, so zinc ion binding is supported.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: 'bind E2s via the first RING-type zinc finger'
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:14623119
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:15236971
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0016567
      label: protein ubiquitination
    evidence_type: IDA
    original_reference_id: PMID:21532592
    review:
      summary: protein ubiquitination is supported by the catalytic role of ARIH1 in
        ubiquitination and downstream ubiquitin-dependent substrate turnover, especially
        as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0031625
      label: ubiquitin protein ligase binding
    evidence_type: IPI
    original_reference_id: PMID:11278816
    review:
      summary: Specific binding to ubiquitin ligase complexes is supported through ARIH1
        cooperation with neddylated CRLs, but it is a complex-association context rather
        than the primary catalytic function.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0031625
      label: ubiquitin protein ligase binding
    evidence_type: IPI
    original_reference_id: PMID:21532592
    review:
      summary: Specific binding to ubiquitin ligase complexes is supported through ARIH1
        cooperation with neddylated CRLs, but it is a complex-association context rather
        than the primary catalytic function.
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Associates with cullin-RING ubiquitin ligase (CRL) complexes
            containing CUL1, CUL2 and CUL3 (PubMed:24076655, PubMed:27565346). Interacts
            with neddylated CUL1 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL2 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL3 (PubMed:24076655, PubMed:27565346). Interacts with
            neddylated CUL4A (PubMed:24076655).
  - term:
      id: GO:0005515
      label: protein binding
    evidence_type: IPI
    original_reference_id: PMID:10521492
    review:
      summary: Generic protein binding is over-broad for ARIH1. The informative
        interaction annotations are E2 binding and CRL/SCF association.
      action: MARK_AS_OVER_ANNOTATED
      reason: Replace generic binding with mechanistically specific E2 or
        ubiquitin-ligase-complex binding where possible.
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0000151
      label: ubiquitin ligase complex
    evidence_type: TAS
    original_reference_id: PMID:10521492
    review:
      summary: ARIH1 forms functional ubiquitin ligase assemblies with neddylated CRLs;
        this broad complex annotation captures that E3-ligase-complex context.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0006511
      label: ubiquitin-dependent protein catabolic process
    evidence_type: TAS
    original_reference_id: PMID:10521492
    review:
      summary: ubiquitin-dependent protein catabolic process is supported by the
        catalytic role of ARIH1 in ubiquitination and downstream ubiquitin-dependent
        substrate turnover, especially as a CRL-associated priming E3.
      action: ACCEPT
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: A major current paradigm is that **neddylated CRLs recruit
            and activate ARIH-family RBR ligases**. Neddylation-induced conformational
            changes in cullins enable catalysis and can relieve ARIH autoinhibition;
            ARIH1 then performs the catalytic ubiquitin transfer while the CRL scaffold
            handles substrate recruitment and E2 positioning.
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
            E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to
            the **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - term:
      id: GO:0019787
      label: ubiquitin-like protein transferase activity
    evidence_type: TAS
    original_reference_id: PMID:10521492
    review:
      summary: 'ubiquitin-like protein transferase activity is retained as a confirmed secondary
        ubiquitin-like/ISGylation function: UniProt explicitly states that ARIH1 acts as the
        ligase involved in ISGylation of EIF4E2, while the dominant core function remains
        ubiquitin transfer with neddylated CRLs.'
      action: KEEP_AS_NON_CORE
      supported_by:
        - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
          supporting_text: Acts as the ligase involved in ISGylation of EIF4E2
            (PubMed:17289916).
        - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
          supporting_text: older literature reported interaction with **UBE2L3 and
            UBE2L6**
      reason: Secondary confirmed ubiquitin-like function, not the dominant ARIH1 core
        activity synthesized from current CRL/RBR literature.
references:
  - id: GO_REF:0000002
    title: Gene Ontology annotation through association of InterPro records with GO
      terms
    findings: []
  - id: GO_REF:0000003
    title: Gene Ontology annotation based on Enzyme Commission mapping
    findings: []
  - id: GO_REF:0000033
    title: Annotation inferences using phylogenetic trees
    findings: []
  - id: GO_REF:0000044
    title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location
      vocabulary mapping, accompanied by conservative changes to GO terms applied by
      UniProt
    findings: []
  - id: GO_REF:0000052
    title: Gene Ontology annotation based on curation of immunofluorescence data
    findings: []
  - id: GO_REF:0000120
    title: Combined Automated Annotation using Multiple IEA Methods
    findings: []
  - id: PMID:10521492
    title: The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact with RING
      finger/IBR motif-containing domains of HHARI and H7-AP1.
    findings: []
  - id: PMID:11278816
    title: Features of the parkin/ariadne-like ubiquitin ligase, HHARI, that regulate
      its interaction with the ubiquitin-conjugating enzyme, Ubch7.
    findings: []
  - id: PMID:14623119
    title: Human homologue of ariadne promotes the ubiquitylation of translation
      initiation factor 4E homologous protein, 4EHP.
    findings: []
  - id: PMID:15236971
    title: Structure of the C-terminal RING finger from a RING-IBR-RING/TRIAD motif
      reveals a novel zinc-binding domain distinct from a RING.
    findings: []
  - id: PMID:21145461
    title: Dynamics of cullin-RING ubiquitin ligase network revealed by systematic
      quantitative proteomics.
    findings: []
  - id: PMID:21532592
    title: UBCH7 reactivity profile reveals parkin and HHARI to be RING/HECT hybrids.
    findings: []
  - id: PMID:21590270
    title: The parkin-like human homolog of Drosophila ariadne-1 (HHARI) can induce
      aggresome formation in mammalian cells and is immunologically detectable in Lewy
      bodies.
    findings: []
  - id: PMID:23059369
    title: Human Homolog of Drosophila Ariadne (HHARI) is a marker of cellular
      proliferation associated with nuclear bodies.
    findings: []
  - id: PMID:23707686
    title: 'Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoinhibition of an Ariadne-family
      E3 and insights into ligation mechanism.'
    findings: []
  - id: PMID:24076655
    title: TRIAD1 and HHARI bind to and are activated by distinct neddylated Cullin-RING
      ligase complexes.
    findings: []
  - id: PMID:27565346
    title: Two Distinct Types of E3 Ligases Work in Unison to Regulate Substrate
      Ubiquitylation.
    findings: []
  - id: PMID:28514442
    title: Architecture of the human interactome defines protein communities and disease
      networks.
    findings: []
  - id: PMID:33961781
    title: Dual proteome-scale networks reveal cell-specific remodeling of the human
      interactome.
    findings: []
  - id: Reactome:R-HSA-1169394
    title: ISGylation of IRF3
    findings: []
  - id: Reactome:R-HSA-1169395
    title: ISGylation of viral protein NS1
    findings: []
  - id: Reactome:R-HSA-1169398
    title: ISGylation of host protein filamin B
    findings: []
  - id: Reactome:R-HSA-1169402
    title: ISGylation of E2 conjugating enzymes
    findings: []
  - id: Reactome:R-HSA-1169403
    title: Interaction of E3 ligase with ISG15:E2 complex
    findings: []
  - id: Reactome:R-HSA-1169405
    title: ISGylation of protein phosphatase 1 beta (PP2CB)
    findings: []
  - id: Reactome:R-HSA-1169406
    title: ISGylation of host proteins
    findings: []
  - id: Reactome:R-HSA-1678843
    title: ISGylation of protein translation regulator 4EHP
    findings: []
  - id: Reactome:R-HSA-9833482
    title: PKR-mediated signaling
    findings: []
  - id: Reactome:R-HSA-9833973
    title: ISGylation of PKR
    findings: []
  - id: Reactome:R-HSA-9837231
    title: ISGylation of BECN1
    findings: []
  - id: Reactome:R-HSA-9927247
    title: ISGylation of DDX58 (RIG-I)
    findings: []
  - id: file:human/ARIH1/ARIH1-deep-research-falcon.md
    title: Falcon deep research synthesis for ARIH1
    findings: []
  - id: file:human/ARIH1/ARIH1-uniprot.txt
    title: UniProt record for ARIH1
    findings: []
core_functions:
  - description: RBR E3 ubiquitin-protein ligase activity that primes ubiquitination of
      CRL-bound substrates in neddylated SCF/CRL assemblies.
    molecular_function:
      id: GO:0061630
      label: ubiquitin protein ligase activity
    directly_involved_in:
      - id: GO:0016567
        label: protein ubiquitination
      - id: GO:0006511
        label: ubiquitin-dependent protein catabolic process
    locations:
      - id: GO:0005737
        label: cytoplasm
      - id: GO:0005829
        label: cytosol
      - id: GO:0005634
        label: nucleus
    in_complex:
      id: GO:0019005
      label: SCF ubiquitin ligase complex
    supported_by:
      - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
        supporting_text: A major current paradigm is that **neddylated CRLs recruit and
          activate ARIH-family RBR ligases**. Neddylation-induced conformational changes
          in cullins enable catalysis and can relieve ARIH autoinhibition; ARIH1 then
          performs the catalytic ubiquitin transfer while the CRL scaffold handles
          substrate recruitment and E2 positioning.
      - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
        supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
          E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to the
          **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
  - description: UBE2L3/UbcH7 binding as the E2-recruitment step of ARIH1 RBR ubiquitin
      transfer.
    molecular_function:
      id: GO:0031624
      label: ubiquitin conjugating enzyme binding
    directly_involved_in:
      - id: GO:0016567
        label: protein ubiquitination
    locations:
      - id: GO:0005737
        label: cytoplasm
      - id: GO:0005634
        label: nucleus
    supported_by:
      - reference_id: file:human/ARIH1/ARIH1-deep-research-falcon.md
        supporting_text: In the best-defined structural/biochemical pathway (SCF–ARIH1
          E3–E3 super-assembly), ubiquitin is transferred from **UBE2L3 (UbcH7)** to the
          **ARIH1 catalytic cysteine** and then to an SCF-bound substrate.
      - reference_id: file:human/ARIH1/ARIH1-uniprot.txt
        supporting_text: 'bind E2s via the first RING-type zinc finger'
proposed_new_terms: []
suggested_questions: []
suggested_experiments: []

ARIH1

Gene Description

Existing Annotations Review

Core Functions

RBR E3 ubiquitin-protein ligase activity that primes ubiquitination of CRL-bound substrates in neddylated SCF/CRL assemblies.

UBE2L3/UbcH7 binding as the E2-recruitment step of ARIH1 RBR ubiquitin transfer.

References

Deep Research

Falcon

Research Report: Human ARIH1 (HHARI) Functional Annotation (UniProt Q9Y4X5)

0) Target verification (critical)

1) Key concepts and definitions (current understanding)

1.1 ARIH1 is an RBR (RING-between-RING) E3 ubiquitin ligase

1.2 Core reaction catalyzed and substrate specificity (functional definition)

1.3 Neddylation and CRL–RBR “E3–E3” cooperation

2) Molecular mechanism of ARIH1 (what it does and how)

2.1 Autoinhibition and activation

2.2 E2 partners (E2-to-E3 handoff)

2.3 Structural mechanism: SCF–ARIH1 E3–E3 super-assembly

2.4 2023 mechanistic consolidation for RBRs (including ARIH1)

3) Biological roles, pathways, and cellular localization

3.1 Proteostasis and cell-cycle control via CRL substrates

3.2 EMT and cancer progression via hnRNP E1/PCBP1 stability

3.3 Translation control connections (context and evidence base)

3.4 Innate immune signaling (emerging/less mature evidence)

3.5 Subcellular localization

4) Recent developments (prioritize 2023–2024)

4.1 2024: refined view of CRL geometry and catalytic partnering

4.2 2024: broader cullin–RBR chimeric assemblies

4.3 2023: mechanistic unification of the RBR family including HHARI

5) Current applications and real-world implementations

5.1 Targeted protein degradation (TPD) and PROTAC ecosystem (ARIH1-adjacent)

5.2 Neddylation as a pharmacologic lever (relevant to ARIH1 activation)

5.3 Disease-oriented implementation: cancer progression mechanisms

6) Expert synthesis and analysis (what authoritative sources imply)

6.1 Primary function (most strongly supported)

6.2 Where the field is still uncertain

6.3 Constraint/essentiality

7) Relevant recent statistics and quantitative data (from available sources)

8) Database-level disease associations (hypothesis-generating)

Summary table

Key visual evidence

Citations

📄 View Raw YAML