ARF1 encodes ADP-ribosylation factor 1, a myristoylated class I ARF-family small GTPase that cycles between cytosolic GDP-bound and membrane-associated GTP-bound states. Active ARF1 acts mainly on Golgi and trans-Golgi network membranes, where it recruits and regulates coat/adaptor and lipid-transfer machinery for vesicle budding, coat disassembly, intra-Golgi traffic, Golgi-to-ER retrograde transport, TGN-to-endosomal/plasma-membrane routes, and glycosphingolipid export. Its major cellular role is regulation of membrane trafficking through the secretory and endomembrane systems rather than serving as a structural coat subunit.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0006886 intracellular protein transport | IBA GO_REF:0000033 | ACCEPT | Summary: Intracellular protein transport is a valid broad process for ARF1-dependent Golgi/TGN and COPI-related trafficking. Reason: This IBA term captures the conserved trafficking role of ARF1. It is broader than the PN retrograde-transport candidate but biologically sound. Supporting Evidence: Reactome:R-HSA-6811434 Retrograde traffic from the cis-Golgi to the ERGIC or the ER is mediated in part by microtubule-directed COPI-coated vesicles PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. |
| GO:0005525 GTP binding | IBA GO_REF:0000033 | ACCEPT | Summary: GTP binding is the nucleotide-binding state required for ARF1 activation and membrane-effector recruitment. Reason: This is a core biochemical property of ARF1 and is directly tied to ARF1-dependent coat recruitment and vesicle budding. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. |
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: Plasma membrane association/activity is reported in signaling and PLD contexts but is not the primary ARF1 compartment. Reason: ARF1 can participate in plasma-membrane-linked signaling or trafficking, but the dominant conserved role is Golgi/TGN membrane trafficking. Supporting Evidence: PMID:8529647 The results indicate that ARF proteins and their nucleotide-exchange factor are apparently involved in the signalling pathway leading from mAChR activation to PLD stimulation in human embryonic kidney cells. |
| GO:0000139 Golgi membrane | IEA GO_REF:0000044 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0003924 GTPase activity | IEA GO_REF:0000002 | ACCEPT | Summary: ARF1 is a canonical small GTPase that binds guanine nucleotide and hydrolyzes GTP as part of its membrane-trafficking cycle. Reason: The GTP/GDP cycle is the core molecular function of ARF1. GTP binding promotes membrane/effector engagement and GTP hydrolysis, stimulated by ARFGAPs and coatomer, drives coat disassembly. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0003925 G protein activity | IEA GO_REF:0000003 | ACCEPT | Summary: ARF1 is an ADP-ribosylation factor family small G protein whose active GTP-bound state recruits trafficking effectors. Reason: Although broader than GTPase activity, small G protein activity is an appropriate molecular-function description for ARF1. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. |
| GO:0005525 GTP binding | IEA GO_REF:0000120 | ACCEPT | Summary: GTP binding is the nucleotide-binding state required for ARF1 activation and membrane-effector recruitment. Reason: This is a core biochemical property of ARF1 and is directly tied to ARF1-dependent coat recruitment and vesicle budding. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. |
| GO:0014069 postsynaptic density | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Synaptic and postsynaptic-density annotations reflect transferred neuronal ARF1/PICK1 biology rather than the core conserved Golgi trafficking function. Reason: These annotations are plausible as specialized neuronal contexts, but they are not the main ARF1 function and are supported here by similarity rather than direct human ARF1 experiments. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0045202 synapse | IEA GO_REF:0000044 | KEEP AS NON CORE | Summary: Synaptic and postsynaptic-density annotations reflect transferred neuronal ARF1/PICK1 biology rather than the core conserved Golgi trafficking function. Reason: These annotations are plausible as specialized neuronal contexts, but they are not the main ARF1 function and are supported here by similarity rather than direct human ARF1 experiments. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0005515 protein binding | IPI PMID:10198630 Brefeldin A acts to stabilize an abortive ARF-GDP-Sec7 domai... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:14654833 Structural snapshots of the mechanism and inhibition of a gu... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:17563369 Structure-based discovery of an inhibitor of Arf activation ... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:19644450 The structural basis of Arf effector specificity: the crysta... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:22981988 The BAR domain protein Arfaptin-1 controls secretory granule... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:31467278 Maximizing binary interactome mapping with a minimal number ... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:35271311 OpenCell: Endogenous tagging for the cartography of human ce... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0005515 protein binding | IPI PMID:36396045 Targeting ARF1-IQGAP1 interaction to suppress colorectal can... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0000287 magnesium ion binding | IEA GO_REF:0000107 | ACCEPT | Summary: Magnesium binding is consistent with ARF1 nucleotide binding and GTPase chemistry. Reason: Small GTPases require Mg2+-coordinated nucleotide binding/hydrolysis; this is a supporting biochemical property rather than a standalone biological role. Supporting Evidence: file:human/ARF1/ARF1-notes.md The magnesium ion binding annotation is retained as a cofactor-level biochemical property of the nucleotide/GTPase mechanism, not as an independent biological role. |
| GO:0005794 Golgi apparatus | IEA GO_REF:0000120 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0005829 cytosol | IEA GO_REF:0000107 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0012505 endomembrane system | IEA GO_REF:0000107 | ACCEPT | Summary: Endomembrane localization is broad but consistent with ARF1 function at Golgi/TGN and related trafficking membranes. Reason: ARF1 acts on Golgi, TGN, and related endomembrane trafficking intermediates; this term is less specific than Golgi membrane but accurate. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. Reactome:R-HSA-6811434 Retrograde traffic from the cis-Golgi to the ERGIC or the ER is mediated in part by microtubule-directed COPI-coated vesicles |
| GO:0030017 sarcomere | IEA GO_REF:0000107 | MARK AS OVER ANNOTATED | Summary: Sarcomere (IEA), transferred from rat Arf1, where it is a direct observation in skeletal muscle (IDA, PMID:14728599). It is not part of the ARF1 Golgi/TGN trafficking model. Reason: The row is an orthology transfer of a direct observation on rat Arf1 in skeletal muscle, from a study of vesicle budding from the endoplasmic reticulum and calsequestrin routing to the sarcoplasmic reticulum (PMID:14728599; not read here). Nothing contradicts the observation, and ARF1 is very highly conserved between rat and human, so the transfer itself is sound. What ARF1 does is recruit coats on Golgi and ER-Golgi membranes; a sarcomere location most likely records where those ARF1-positive membranes sit in muscle fibres rather than ARF1 being a component of the contractile unit, so the term over-states the finding instead of being wrong. Supporting Evidence: file:human/ARF1/ARF1-notes.md Sarcomere localization and mitotic cleavage furrow ingression are not supported as core ARF1 biology in this review; the curated evidence supports Golgi/TGN endomembrane trafficking instead. |
| GO:0032991 protein-containing complex | IEA GO_REF:0000107 | MARK AS OVER ANNOTATED | Summary: ARF1 forms transient regulatory complexes with effectors and regulators, but a generic protein-containing complex annotation is not informative. Reason: This term loses the biology of an active small GTPase recruiting coat/adaptor machinery. It should not be treated as a core complex-membership assertion. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein-containing complex annotations are treated as over-annotated because ARF1 forms transient regulatory complexes with coat, adaptor, GEF, and GAP machinery rather than acting as a stable structural complex subunit. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:1990386 mitotic cleavage furrow ingression | IEA GO_REF:0000107 | MARK AS OVER ANNOTATED | Summary: Mitotic cleavage furrow ingression is a possible specialized small-GTPase trafficking context but is not supported here by direct ARF1 evidence. Reason: The annotation is too specific for the available electronically transferred evidence and should not be considered core ARF1 biology. Supporting Evidence: file:human/ARF1/ARF1-notes.md Sarcomere localization and mitotic cleavage furrow ingression are not supported as core ARF1 biology in this review; the curated evidence supports Golgi/TGN endomembrane trafficking instead. |
| GO:0003925 G protein activity | IDA PMID:17687330 Glycosphingolipid synthesis requires FAPP2 transfer of gluco... | ACCEPT | Summary: ARF1 is an ADP-ribosylation factor family small G protein whose active GTP-bound state recruits trafficking effectors. Reason: Although broader than GTPase activity, small G protein activity is an appropriate molecular-function description for ARF1. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. |
| GO:0046836 glycolipid transport | IDA PMID:17687330 Glycosphingolipid synthesis requires FAPP2 transfer of gluco... | KEEP AS NON CORE | Summary: ARF1 regulates FAPP2-dependent glucosylceramide transfer and glycosphingolipid synthesis/export. Reason: The process is experimentally supported, but it is a specialized lipid-trafficking context downstream of ARF1 effector recruitment rather than the broad conserved core role. Supporting Evidence: PMID:17687330 the whole glycosphingolipid synthetic pathway sensitive to regulation by phosphatidylinositol 4-phosphate and ARF1. |
| GO:1903292 protein localization to Golgi membrane | IDA PMID:17687330 Glycosphingolipid synthesis requires FAPP2 transfer of gluco... | ACCEPT | Summary: ARF1 promotes Golgi/TGN localization of PH-domain effectors such as FAPP proteins by cooperating with phosphatidylinositol 4-phosphate. Reason: Effector recruitment to Golgi/TGN membranes is a central consequence of ARF1 activation and is directly supported by the FAPP studies. Supporting Evidence: PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. PMID:17687330 the whole glycosphingolipid synthetic pathway sensitive to regulation by phosphatidylinositol 4-phosphate and ARF1. |
| GO:0005765 lysosomal membrane | IDA PMID:41293316 Loss of ARF5 impairs recovery after lysosomal damage. | KEEP AS NON CORE | Summary: ARF1 can relocalize to damaged lysosomal membranes in LLOME-treated cells. Reason: The localization is experimentally observed, but the same study identifies ARF5, not ARF1, as the isoform required for lysosomal recovery, so this should not be treated as a core ARF1 function. Supporting Evidence: PMID:41293316 we found that ARF1, ARF5, and ARF6 localize to lysosomal membranes following L-leucyl-L-leucine methyl ester (LLOME)-induced permeabilization. |
| GO:0160281 cytoplasmic side of trans-Golgi network membrane | IDA PMID:17687330 Glycosphingolipid synthesis requires FAPP2 transfer of gluco... | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | EXP PMID:17555535 Specificity, promiscuity and localization of ARF protein int... | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0003924 GTPase activity | EXP PMID:10022920 Identification of a new Pyk2 target protein with Arf-GAP act... | ACCEPT | Summary: This paper identifies a Golgi/plasma-membrane ARF-GAP with activity toward ARF1, supporting ARF1 as a regulated GTPase. Reason: GTPase activity is the core ARF1 molecular function; the paper supports regulation of ARF1 GTPase cycling by ARF-GAPs. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0003924 GTPase activity | EXP PMID:10102276 Structural and functional analysis of the ARF1-ARFGAP comple... | ACCEPT | Summary: ARF1 is a canonical small GTPase that binds guanine nucleotide and hydrolyzes GTP as part of its membrane-trafficking cycle. Reason: The GTP/GDP cycle is the core molecular function of ARF1. GTP binding promotes membrane/effector engagement and GTP hydrolysis, stimulated by ARFGAPs and coatomer, drives coat disassembly. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0003924 GTPase activity | EXP PMID:15107860 FAPPs control Golgi-to-cell-surface membrane traffic by bind... | ACCEPT | Summary: ARF1 is a canonical small GTPase that binds guanine nucleotide and hydrolyzes GTP as part of its membrane-trafficking cycle. Reason: The GTP/GDP cycle is the core molecular function of ARF1. GTP binding promotes membrane/effector engagement and GTP hydrolysis, stimulated by ARFGAPs and coatomer, drives coat disassembly. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0003924 GTPase activity | EXP PMID:8253837 Hydrolysis of bound GTP by ARF protein triggers uncoating of... | ACCEPT | Summary: ARF1 is a canonical small GTPase that binds guanine nucleotide and hydrolyzes GTP as part of its membrane-trafficking cycle. Reason: The GTP/GDP cycle is the core molecular function of ARF1. GTP binding promotes membrane/effector engagement and GTP hydrolysis, stimulated by ARFGAPs and coatomer, drives coat disassembly. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0014069 postsynaptic density | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: Synaptic and postsynaptic-density annotations reflect transferred neuronal ARF1/PICK1 biology rather than the core conserved Golgi trafficking function. Reason: These annotations are plausible as specialized neuronal contexts, but they are not the main ARF1 function and are supported here by similarity rather than direct human ARF1 experiments. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0003924 GTPase activity | TAS Reactome:R-HSA-8847883 | ACCEPT | Summary: ARF1 is a canonical small GTPase that binds guanine nucleotide and hydrolyzes GTP as part of its membrane-trafficking cycle. Reason: The GTP/GDP cycle is the core molecular function of ARF1. GTP binding promotes membrane/effector engagement and GTP hydrolysis, stimulated by ARFGAPs and coatomer, drives coat disassembly. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0005515 protein binding | IPI PMID:12668765 Structure of the GAT domain of human GGA1: a syntaxin amino-... | MARK AS OVER ANNOTATED | Summary: ARF-dependent GGA localization is supported, but generic protein binding is too vague. Reason: The GGA GAT-domain interaction is biologically real, but ARF1 should not be curated mainly as protein binding; its informative role is active small-GTPase recruitment of trafficking adaptors. Supporting Evidence: PMID:12668765 The ARF binding site is located in the N-terminal extension and is separate from the core three-helix bundle. |
| GO:0019904 protein domain specific binding | IMP PMID:12668765 Structure of the GAT domain of human GGA1: a syntaxin amino-... | KEEP AS NON CORE | Summary: ARF1 binding to the GGA1 GAT domain is a characterized adaptor-recruitment interaction, but it is not the core ARF1 molecular function. Reason: The IMP-supported GGA1-GAT interaction is real and relevant to ARF-dependent adaptor recruitment, but GTPase activity and trafficking-process annotations better capture ARF1 core function. Supporting Evidence: PMID:12668765 The ARF binding site is located in the N-terminal extension and is separate from the core three-helix bundle. |
| GO:0003924 GTPase activity | IDA PMID:12771146 The tyrosine kinase Pyk2 regulates Arf1 activity by phosphor... | ACCEPT | Summary: ASAP1 phosphorylation modulates GAP activity and hence ARF1 activity. Reason: This directly supports ARF1 as a regulated GTPase in signaling/trafficking pathways. Supporting Evidence: PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0098586 cellular response to virus | IMP PMID:28389568 Hepatitis C virus triggers Golgi fragmentation and autophagy... | KEEP AS NON CORE | Summary: The viral-response annotation reflects HCV-induced Golgi remodeling through IRGM/GBF1/ARF-GTPase circuitry. Reason: This is a real infection-specific context but not the conserved core function of ARF1. Supporting Evidence: PMID:28389568 which normally operates in Golgi membrane dynamics and vesicle coating in resting cells. |
| GO:0032991 protein-containing complex | IMP PMID:12668765 Structure of the GAT domain of human GGA1: a syntaxin amino-... | MARK AS OVER ANNOTATED | Summary: ARF1 forms transient regulatory complexes with effectors and regulators, but a generic protein-containing complex annotation is not informative. Reason: This term loses the biology of an active small GTPase recruiting coat/adaptor machinery. It should not be treated as a core complex-membership assertion. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein-containing complex annotations are treated as over-annotated because ARF1 forms transient regulatory complexes with coat, adaptor, GEF, and GAP machinery rather than acting as a stable structural complex subunit. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. |
| GO:0005515 protein binding | IPI PMID:17956946 Dissecting the role of the ARF guanine nucleotide exchange f... | MARK AS OVER ANNOTATED | Summary: The physical interaction is real or plausible, but generic protein binding does not describe ARF1 molecular function. Reason: Protein binding is non-informative for this gene. ARF1 should be represented by GTP binding/GTPase activity and by specific trafficking processes rather than generic interaction terms. Supporting Evidence: file:human/ARF1/ARF1-notes.md Generic protein binding annotations are treated as over-annotated because ARF1 has many real effectors and regulators, but the term does not capture the informative activity: regulated small-GTPase recruitment of trafficking machinery. |
| GO:0031252 cell leading edge | IDA PMID:22573891 GBF1 bears a novel phosphatidylinositol-phosphate binding mo... | KEEP AS NON CORE | Summary: Cell-leading-edge localization is plausible in chemotactic signaling contexts involving PI3K/GBF1/ARF1 activation. Reason: This is a specialized signaling/localization context, not the central Golgi/TGN ARF1 role. Supporting Evidence: PMID:22573891 is primarily responsible for Arf1 activation upon GPCR stimulation and is important for neutrophil chemotaxis and superoxide production. |
| GO:0005925 focal adhesion | HDA PMID:21423176 Analysis of the myosin-II-responsive focal adhesion proteome... | MARK AS OVER ANNOTATED | Summary: This high-throughput localization is compatible with broad trafficking biology but does not define ARF1 core function. Reason: High-throughput compartment detections should not outweigh the well-supported Golgi/TGN trafficking model for ARF1. Supporting Evidence: file:human/ARF1/ARF1-notes.md High-throughput-only focal adhesion, extracellular exosome, and RNA-binding annotations are treated as over-annotated because they do not define the established ARF1 Golgi/TGN trafficking function. |
| GO:0070062 extracellular exosome | HDA PMID:23533145 In-depth proteomic analyses of exosomes isolated from expres... | KEEP AS NON CORE | Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions. Reason: Myristoylated cytosolic small GTPase that cycles onto membranes. Cytosolic protein with lipid or membrane-protein binding ability; MISEV2018 (PMID:30637094) category 2a lists such proteins (ESCRT components, ALIX, annexins, HSPA8 and others) as expected EV contents. True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: MARK_AS_OVER_ANNOTATED.) |
| GO:0003723 RNA binding | HDA PMID:22681889 The mRNA-bound proteome and its global occupancy profile on ... | MARK AS OVER ANNOTATED | Summary: RNA binding is from a high-throughput mRNA-bound proteome study and is not a known ARF1 biochemical function. Reason: The canonical ARF1 function is guanine nucleotide binding/hydrolysis and membrane trafficking; RNA binding should not be promoted without targeted validation. Supporting Evidence: file:human/ARF1/ARF1-notes.md High-throughput-only focal adhesion, extracellular exosome, and RNA-binding annotations are treated as over-annotated because they do not define the established ARF1 Golgi/TGN trafficking function. |
| GO:0002090 regulation of receptor internalization | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: regulation of receptor internalization reflects transferred neuronal PICK1/AMPAR-related ARF1 biology. Reason: These neuronal terms are plausible specialized contexts but are not the conserved core function of ARF1 and are supported by similarity transfer in this GOA set. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0034315 regulation of Arp2/3 complex-mediated actin nucleation | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: regulation of Arp2/3 complex-mediated actin nucleation reflects transferred neuronal PICK1/AMPAR-related ARF1 biology. Reason: These neuronal terms are plausible specialized contexts but are not the conserved core function of ARF1 and are supported by similarity transfer in this GOA set. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0060292 long-term synaptic depression | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: long-term synaptic depression reflects transferred neuronal PICK1/AMPAR-related ARF1 biology. Reason: These neuronal terms are plausible specialized contexts but are not the conserved core function of ARF1 and are supported by similarity transfer in this GOA set. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0097061 dendritic spine organization | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: dendritic spine organization reflects transferred neuronal PICK1/AMPAR-related ARF1 biology. Reason: These neuronal terms are plausible specialized contexts but are not the conserved core function of ARF1 and are supported by similarity transfer in this GOA set. Supporting Evidence: file:human/ARF1/ARF1-notes.md Neuronal annotations transferred from orthology, including postsynaptic density, synapse, receptor internalization, Arp2/3 regulation, long-term synaptic depression, and dendritic spine organization, are retained only as non-core specialized contexts. |
| GO:0070062 extracellular exosome | HDA PMID:19199708 Proteomic analysis of human parotid gland exosomes by multid... | KEEP AS NON CORE | Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions. Reason: Myristoylated cytosolic small GTPase that cycles onto membranes. Cytosolic protein with lipid or membrane-protein binding ability; MISEV2018 (PMID:30637094) category 2a lists such proteins (ESCRT components, ALIX, annexins, HSPA8 and others) as expected EV contents. True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: MARK_AS_OVER_ANNOTATED.) |
| GO:0070062 extracellular exosome | HDA PMID:20458337 MHC class II-associated proteins in B-cell exosomes and pote... | KEEP AS NON CORE | Summary: Detected in an extracellular-vesicle proteome. The protein is plausible EV content, but this is not where it functions. Reason: Myristoylated cytosolic small GTPase that cycles onto membranes. Cytosolic protein with lipid or membrane-protein binding ability; MISEV2018 (PMID:30637094) category 2a lists such proteins (ESCRT components, ALIX, annexins, HSPA8 and others) as expected EV contents. True, but not its core location. (Manual re-review for OMICS_EVIDENCE, 2026-10-10; previous action: MARK_AS_OVER_ANNOTATED.) |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-1675883 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-1676152 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-2130619 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-350769 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-421831 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-421833 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-432706 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-432712 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-8847875 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-8847880 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-8847883 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-8870499 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-8951498 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0000139 Golgi membrane | TAS Reactome:R-HSA-9845055 | ACCEPT | Summary: Golgi membrane localization is central to ARF1 function in coat recruitment and Golgi/TGN trafficking. Reason: ARF1 cycles between cytosol and Golgi/TGN membranes, where the active GTP-bound form recruits coat and lipid-metabolism effectors. Supporting Evidence: PMID:17555535 ARF1 but not ARF5 or 6 enhanced the stimulatory effect of PI4Kbeta on regulated exocytosis. PMID:15107860 FAPPs are essential components of a PtdIns(4)P- and ARF-regulated machinery. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-200879 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-350769 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-421831 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-432706 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-8950173 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0005829 cytosol | TAS Reactome:R-HSA-8951498 | ACCEPT | Summary: Cytosolic localization is consistent with the soluble GDP-bound pool of ARF1 between membrane-recruitment cycles. Reason: ARF1 is a peripheral, myristoylated small GTPase that cycles between cytosol and membranes; cytosol is therefore a real localization, though not the active membrane-bound state. Supporting Evidence: file:human/ARF1/ARF1-notes.md Cytosol and endomembrane annotations are accurate localization context for a cycling peripheral membrane GTPase, but the active functional emphasis remains Golgi/TGN membrane recruitment and coat/adaptor regulation. |
| GO:0006878 intracellular copper ion homeostasis | IMP PMID:21034850 The ADP-ribosylation factor 1 (Arf1) is involved in regulati... | KEEP AS NON CORE | Summary: ARF1-dependent trafficking affects copper uptake and CTR1 distribution. Reason: This is experimentally supported but appears to be a cargo/trafficking consequence rather than ARF1's primary molecular role. Supporting Evidence: PMID:21034850 Arf1-dependent trafficking pathways are therefore required for optimal copper uptake efficiency. |
| GO:0005886 plasma membrane | TAS PMID:8529647 Evidence for ADP-ribosylation-factor-mediated activation of ... | KEEP AS NON CORE | Summary: Plasma membrane association/activity is reported in signaling and PLD contexts but is not the primary ARF1 compartment. Reason: ARF1 can participate in plasma-membrane-linked signaling or trafficking, but the dominant conserved role is Golgi/TGN membrane trafficking. Supporting Evidence: PMID:8529647 The results indicate that ARF proteins and their nucleotide-exchange factor are apparently involved in the signalling pathway leading from mAChR activation to PLD stimulation in human embryonic kidney cells. |
| GO:0006890 retrograde vesicle-mediated transport, Golgi to endoplasmic reticulum | TAS Reactome:R-HSA-6811434 | NEW | Summary: PN projection and Reactome support adding the specific Golgi-to-ER retrograde transport process for ARF1. Reason: ARF1 is the regulatory small GTPase that promotes coat recruitment and controls COPI coat cycling. This supports a process-level retrograde transport annotation, while the projected COPI vesicle coat component term should not be added because ARF1 is not a coatomer subunit. Supporting Evidence: Reactome:R-HSA-6811434 Retrograde traffic from the cis-Golgi to the ERGIC or the ER is mediated in part by microtubule-directed COPI-coated vesicles PMID:8253837 The cycle of nucleotide exchange and hydrolysis by a small GTP-binding protein, ADP-ribosylation factor (ARF), helps to provide vectoriality to vesicle transport. PMID:10102276 a tripartite complex controls the GTP hydrolysis reaction triggering disassembly of COPI vesicle coats. file:human/ARF1/ARF1-notes.md The projected `GO:0030126 COPI vesicle coat` should not be added for ARF1. |
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Download this section (compressed HTML)Q: Should PN-to-GO propagation for `COPI coating and uncoating` distinguish structural coatomer subunits from regulatory GTPases such as ARF1 so that `GO:0030126 COPI vesicle coat` is not projected to ARF1?
Q: Would a process term for ARF-dependent COPI coat assembly/disassembly better capture ARF1 than the cellular-component term `COPI vesicle coat`?
Q: Should ARF1's role in terminating cGAS-STING signaling via retrograde Golgi-to-ER recycling of STING be captured as a distinct negative-regulation-of-type-I-interferon process annotation, or does it remain a downstream consequence of the core retrograde-transport function?
Experiment: Use acute endogenous ARF1 depletion or rapid ARF1 inactivation together with rescue by GTPase-cycle mutants, then quantify KDEL receptor/chaperone retrieval from Golgi to ER and COPI coat recruitment/uncoating kinetics.
Hypothesis: ARF1 GTPase cycling is required for efficient Golgi-to-ER retrieval of escaped ER proteins, supporting the retrograde-transport annotation without implying ARF1 is a structural COPI coat component.
Type: cell biology
Experiment: Perform proximity labeling of endogenous ARF1 during synchronized COPI budding/uncoating and compare enrichment of coatomer subunits, ARFGAPs, KDEL receptors, and cargo proteins across GTP-locked and GDP-locked ARF1 states.
Hypothesis: ARF1 associates transiently with COPI coat-cycle machinery as a regulatory GTPase rather than as a stable COPI coat constituent.
Type: proteomics
Experiment: Express disease-associated GTPase-defective ARF1 variants (e.g. R99C/R99H) in ARF1-edited cells and quantify STING retrograde Golgi-to-ER recycling, mitochondrial morphology and mtDNA release, and interferon-stimulated gene induction relative to wild-type ARF1 rescue.
Hypothesis: Loss of ARF1 GTPase cycling impairs STING retrograde transport and mitochondrial integrity, causing cGAS-STING-dependent type I interferon hyperactivation, distinct from ARF1's bulk Golgi/TGN coat-recruitment role.
Type: cell biology
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