TRIM5

UniProt ID: Q9C035
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

TRIM5 (tripartite motif-containing protein 5; the antiviral isoform is TRIM5alpha) is a cytoplasmic RING-type E3 ubiquitin ligase of the TRIM/RBCC family that functions both as a capsid-specific retroviral restriction factor and as an innate immune pattern-recognition receptor. Its RBCC architecture comprises an N-terminal RING-type zinc finger that confers E3 ubiquitin ligase activity (EC 2.3.2.27), a B-box-type zinc finger and a coiled-coil that drive the higher- and lower-order self-multimerization required for activity, and a C-terminal B30.2/PRYSPRY (SPRY) domain that directly recognizes the assembled retroviral capsid lattice. Through the PRYSPRY domain TRIM5alpha binds the hexameric capsid lattice of incoming non-host-adapted retroviruses and blocks infection at an early post-entry step, before reverse transcription; polymorphisms in the PRYSPRY domain account for the species-specific spectrum of restriction (human TRIM5alpha restricts N-tropic MLV, EIAV, SIVmac, FIV and BIV but only weakly HIV-1). Capsid lattice binding also triggers TRIM5's RING E3 ligase activity: together with the UBE2V1-UBE2N (UBC13-UEV1A) E2 complex it synthesizes unanchored Lys63-linked polyubiquitin chains that activate the TAK1 (MAP3K7)-TAB2-TAB3 kinase complex by autophosphorylation, inducing NF-kappaB- and AP-1/MAPK-responsive inflammatory genes and thereby acting as a sensor that links capsid detection to innate immune signaling. TRIM5alpha is itself regulated by ubiquitination (RING/UBE2D2-dependent autoubiquitination, monoubiquitination by TRIM21) and undergoes rapid proteasome-dependent turnover upon engaging restriction-sensitive virus. It additionally functions in selective ("precision") autophagy: it acts as a platform that assembles and activates the autophagy regulators ULK1 and BECN1 (Beclin-1, by dissociating it from BCL2 and TAB2) and as a selective autophagy receptor that directly recognizes the HIV-1 capsid protein p24 and delivers it for autophagic degradation, interacting with SQSTM1/p62 and the ATG8 family proteins GABARAP/GABARAPL1/GABARAPL2 and MAP1LC3A/C. TRIM5alpha localizes predominantly to cytoplasmic bodies, where it can form homodimers and homotrimers and colocalizes with proteasomal subunits and SQSTM1.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005737 cytoplasm
IBA
GO_REF:0000033
ACCEPT
Summary: Phylogenetic inference of cytoplasmic localization, where TRIM5alpha acts in cytoplasmic bodies.
Reason: TRIM5alpha is predominantly cytoplasmic and acts there (capsid recognition, signaling, autophagy); strongly supported experimentally.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0045087 innate immune response
IBA
GO_REF:0000033
ACCEPT
Summary: Phylogenetic inference of involvement in innate immunity; TRIM5alpha both restricts retroviruses and activates innate immune signaling.
Reason: Core biological process; TRIM5alpha is an innate immune sensor of the retroviral capsid lattice that activates NF-kB/MAPK signaling.
Supporting Evidence:
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid lattice
GO:0010468 regulation of gene expression
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Generic regulation-of-gene-expression term inherited phylogenetically; downstream consequence of TRIM5-driven NF-kB/MAPK activation.
Reason: Correct but overly generic; the specific positive regulation of NF-kB signaling and MAPK cascade annotations better capture the mechanism.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Activation of the MAP3K7/TAK1 complex by autophosphorylation
GO:0061630 ubiquitin protein ligase activity
IBA
GO_REF:0000033
ACCEPT
Summary: Phylogenetic inference of RING E3 ubiquitin ligase activity, consistent with the experimentally demonstrated RING-dependent ligase activity.
Reason: Core molecular function; the RING domain confers E3 ligase activity essential for restriction, autoubiquitination and signaling.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
The RING-type zinc finger domain confers E3 ubiquitin ligase activity and is essential for retrovirus restriction activity, autoubiquitination
GO:0046596 regulation of viral entry into host cell
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Phylogenetic inference of regulation of viral entry; TRIM5alpha restricts retroviruses but acts after entry, before reverse transcription.
Reason: TRIM5alpha blocks an early post-entry (uncoating/pre-reverse-transcription) step rather than viral entry itself; the restriction role is better captured by host-mediated suppression of symbiont invasion and defense response to virus.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Blocks viral replication early in the life cycle, after viral entry but before reverse transcription
GO:0019901 protein kinase binding
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Phylogenetic inference of protein kinase binding; TRIM5alpha binds the TAK1 kinase complex and ULK1.
Reason: Real and functionally relevant (TAK1/MAP3K7, ULK1) but the informative functions are the downstream signaling activation and autophagy regulation.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
MAP3K7/TAK1, TAB2 and TAB3
GO:0032880 regulation of protein localization
IBA
GO_REF:0000033
KEEP AS NON CORE
Summary: Phylogenetic inference of regulation of protein localization, consistent with the IMP annotation from the autophagy study.
Reason: Supported but a broad process term; reflects TRIM5's autophagy-platform role rather than a core dedicated function.
Supporting Evidence:
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic substrates by direct recognition
GO:0042803 protein homodimerization activity
IBA
GO_REF:0000033
ACCEPT
Summary: Phylogenetic inference of homodimerization; TRIM5alpha forms homodimers and homotrimers essential for restriction activity.
Reason: Core molecular function; self-association (coiled-coil-mediated dimerization plus B-box-driven higher-order multimerization) is essential for capsid-lattice recognition and restriction.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Can form homodimers and homotrimers
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IBA
GO_REF:0000033
ACCEPT
Summary: Phylogenetic inference of positive regulation of NF-kB signaling, consistent with the experimental IMP/IDA evidence.
Reason: Core biological process; capsid sensing triggers TRIM5-mediated K63-Ub/TAK1 activation that induces NF-kB.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Activation of the MAP3K7/TAK1 complex by autophosphorylation
GO:0005634 nucleus
IEA
GO_REF:0000044
MARK AS OVER ANNOTATED
Summary: Electronic transfer of a nuclear localization that is only "By similarity" in UniProt (partial nuclear pool seen with TRIM22/TRIM27 coexpression).
Reason: Human TRIM5alpha is predominantly cytoplasmic; nuclear localization is only by similarity (UniProtKB:Q0PF16) and context-dependent, not a core or robustly supported localization.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
partial nuclear localization is observed in the presence of TRIM22 or TRIM27
GO:0005737 cytoplasm
IEA
GO_REF:0000044
ACCEPT
Summary: Electronic transfer of cytoplasmic localization from the UniProt subcellular location; the core compartment.
Reason: Correct core localization; redundant with experimental IDA cytoplasm annotations.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0008270 zinc ion binding
IEA
GO_REF:0000002
KEEP AS NON CORE
Summary: InterPro-based electronic assignment of zinc ion binding by the RING and B-box zinc fingers.
Reason: Correct (RING and B-box coordinate Zn2+) and underpins ligase/multimerization, but generic; the informative MF is ubiquitin ligase activity.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
/note="RING-type"
GO:0042802 identical protein binding
IEA
GO_REF:0000117
KEEP AS NON CORE
Summary: ARBA machine-learning assignment of identical protein binding, reflecting TRIM5 self-association.
Reason: Correct (TRIM5 self-associates) but redundant with and less informative than the protein homodimerization activity annotation.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Can form homodimers and homotrimers
GO:0045893 positive regulation of DNA-templated transcription
IEA
GO_REF:0000108
MARK AS OVER ANNOTATED
Summary: Inter-ontology electronic inference from the transcription coactivator activity annotation.
Reason: Derived from the over-interpreted transcription coactivator annotation; TRIM5 acts upstream in NF-kB/MAPK signaling rather than as a direct DNA-templated transcriptional activator.
Supporting Evidence:
PMID:23077300
to induce NF-ΞΊB and MAP kinase (MAPK) signaling
GO:0061630 ubiquitin protein ligase activity
IEA
GO_REF:0000003
ACCEPT
Summary: EC 2.3.2.27-based electronic assignment of ubiquitin protein ligase activity; core function.
Reason: Core molecular function corroborated by experimental RING-dependent ligase activity.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
EC=2.3.2.27
GO:0005515 protein binding
IPI
PMID:22493164
Systematic analysis of dimeric E3-RING interactions reveals ...
KEEP AS NON CORE
Summary: Interaction from a systematic dimeric E3-RING interaction screen. Bare protein binding is uninformative.
Reason: Records a real RING-RING interaction but bare protein binding is uninformative per curation guidelines.
Supporting Evidence:
PMID:22493164
Systematic analysis of dimeric E3-RING interactions
GO:0005515 protein binding
IPI
PMID:25203322
PKD1 phosphorylation-dependent degradation of SNAIL by SCF-F...
KEEP AS NON CORE
Summary: Interaction reported in an SCF-FBXO11/SNAIL study (TRIM5 appears as an interactor). Bare protein binding is uninformative.
Reason: Bare protein binding is uninformative; not a core TRIM5 function.
Supporting Evidence:
PMID:25203322
PKD1 phosphorylation-dependent degradation of SNAIL by SCF-FBXO11
GO:0005515 protein binding
IPI
PMID:26618866
βˆ†F508 CFTR interactome remodelling promotes rescue of cystic...
KEEP AS NON CORE
Summary: Interaction from a CFTR interactome remodeling study (TRIM5 interacts with CFTR per IntAct). Bare protein binding is uninformative.
Reason: High-throughput interactome interaction; bare protein binding is uninformative.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Q9C035; P13569: CFTR; NbExp=3
GO:0005515 protein binding
IPI
PMID:35156780
CFTR interactome mapping using the mammalian membrane two-hy...
KEEP AS NON CORE
Summary: Interaction from a CFTR mammalian-membrane-two-hybrid screen. Bare protein binding is uninformative.
Reason: High-throughput interactome interaction; bare protein binding is uninformative.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Q9C035; P13569: CFTR; NbExp=3
GO:0042802 identical protein binding
IPI
PMID:22493164
Systematic analysis of dimeric E3-RING interactions reveals ...
KEEP AS NON CORE
Summary: TRIM5-TRIM5 self-interaction detected in the E3-RING dimer screen.
Reason: Correct self-association but redundant with and less informative than protein homodimerization activity.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Q9C035; Q9C035: TRIM5; NbExp=3
GO:0042802 identical protein binding
IPI
PMID:22829933
TRIM27 negatively regulates NOD2 by ubiquitination and prote...
KEEP AS NON CORE
Summary: Self-interaction / TRIM-TRIM interaction reported in a TRIM27/NOD2 study.
Reason: Correct self-association but redundant with the homodimerization annotation.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Can form homodimers and homotrimers
GO:0140374 antiviral innate immune response
IDA
PMID:18248090
TRIM E3 ligases interfere with early and late stages of the ...
ACCEPT
Summary: Direct evidence that TRIM5 functions in the antiviral innate immune response (retroviral restriction screen). Core process.
Reason: Core biological process; TRIM5alpha is an antiviral restriction factor and innate immune effector.
Supporting Evidence:
PMID:18248090
Members of the TRIpartite interaction Motif (TRIM) family of E3 ligases have been shown to exhibit antiviral activities
GO:0036464 cytoplasmic ribonucleoprotein granule
IDA
PMID:20357094
p62/sequestosome-1 associates with and sustains the expressi...
KEEP AS NON CORE
Summary: Localization to cytoplasmic RNP granules/P-bodies reported in the SQSTM1/p62 study.
Reason: Experimentally observed but a specialized sub-compartment; the core localization is cytoplasmic bodies. Defer to curator who read the full text.
Supporting Evidence:
PMID:20357094
p62/sequestosome-1 associates with and sustains the expression of retroviral restriction factor TRIM5alpha
GO:0016567 protein ubiquitination
IEA
GO_REF:0000041
KEEP AS NON CORE
Summary: UniPathway-derived general protein ubiquitination process.
Reason: Correct but generic; the specific K63-linked ubiquitination annotation better captures the activity.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
PATHWAY: Protein modification; protein ubiquitination.
GO:0005829 cytosol
IDA
GO_REF:0000052
ACCEPT
Summary: Immunofluorescence-based (HPA) cytosolic localization, consistent with the core cytoplasmic site of action.
Reason: Correct cytosolic localization; consistent with cytoplasmic body localization.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0005634 nucleus
ISS
GO_REF:0000024
MARK AS OVER ANNOTATED
Summary: Sequence-similarity transfer of nuclear localization, matching the "By similarity" nuclear note in UniProt.
Reason: Nuclear localization for human TRIM5alpha is only by similarity and context-dependent (TRIM22/TRIM27 coexpression); the protein is predominantly cytoplasmic.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
partial nuclear localization is observed in the presence of TRIM22 or TRIM27
GO:0003713 transcription coactivator activity
IDA
PMID:23077300
TRIM protein-mediated regulation of inflammatory and innate ...
MARK AS OVER ANNOTATED
Summary: Assigned from a TRIM-family NF-kB/AP-1/IFN activation screen; reflects TRIM5-driven TAK1/NF-kB signaling rather than direct transcriptional coactivation.
Reason: TRIM5 acts upstream as a signaling activator (TAK1->NF-kB/MAPK), not as a DNA-associated transcription coactivator; this MF over-interprets the signaling phenotype.
Supporting Evidence:
PMID:23077300
to induce NF-ΞΊB and MAP kinase (MAPK) signaling
GO:0044790 suppression of viral release by host
IDA
PMID:18248090
TRIM E3 ligases interfere with early and late stages of the ...
MARK AS OVER ANNOTATED
Summary: Late-stage (viral release) suppression assigned from a broad TRIM screen; for TRIM5alpha the validated dominant activity is early post-entry restriction.
Reason: The screen found late-stage effects for several TRIMs (e.g. TRIM25/31/62); TRIM5alpha's well-established mechanism is early post-entry capsid restriction, so a "viral release" role is weakly supported for TRIM5.
Supporting Evidence:
PMID:18248090
many TRIM proteins affected late stages of the viral life cycle
GO:0046597 host-mediated suppression of symbiont invasion
IDA
PMID:18248090
TRIM E3 ligases interfere with early and late stages of the ...
ACCEPT
Summary: Direct evidence that TRIM5 suppresses retroviral invasion (early restriction). Core restriction process.
Reason: Core biological process; captures the capsid-dependent post-entry restriction of incoming retroviruses.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Capsid-specific restriction factor that prevents infection
GO:0005515 protein binding
IPI
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
KEEP AS NON CORE
Summary: Autophagy-machinery interactions (ULK1, BECN1, SQSTM1, ATG8 proteins) from the precision-autophagy study. Bare protein binding is uninformative.
Reason: Records real, functionally important autophagy interactions but bare protein binding is uninformative; better captured by the adaptor-activity and autophagy annotations.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Interacts with ULK1 (phosphorylated form), GABARAP, GABARAPL1, GABARAPL2,
GO:0005737 cytoplasm
IDA
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
ACCEPT
Summary: Direct evidence of cytoplasmic localization from the autophagy study. Core localization.
Reason: Correct core localization, experimentally demonstrated.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0006914 autophagy
IDA
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
ACCEPT
Summary: Direct evidence that TRIM5alpha functions in autophagy, as a selective autophagy receptor and as a platform activating ULK1/BECN1. Core process.
Reason: Core biological process; TRIM5alpha regulates autophagy and acts as a selective autophagy receptor for the HIV-1 capsid.
Supporting Evidence:
PMID:25127057
TRIM5Ξ± acts as a selective autophagy receptor
GO:0098792 xenophagy
IDA
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
NEW
Summary: TRIM5alpha delivers the HIV-1 capsid, a foreign cytosolic viral cargo, for selective autophagic degradation.
Reason: PN correctly flagged that the existing autophagy annotation is generic for this role. Xenophagy is the more specific process term for autophagic degradation of a cytosolic viral capsid.
Supporting Evidence:
PMID:25127057
TRIM5Ξ± delivered its cognate cytosolic target, a viral capsid protein, for autophagic degradation
GO:0019901 protein kinase binding
IPI
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
KEEP AS NON CORE
Summary: Direct interaction with the kinase ULK1 (phosphorylated form) in the autophagy study.
Reason: Real and functionally relevant (ULK1) but the informative function is the autophagy-platform/adaptor role.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Interacts with ULK1 (phosphorylated form)
GO:0030674 protein-macromolecule adaptor activity
IPI
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
ACCEPT
Summary: TRIM5alpha bridges autophagy machinery (ULK1, BECN1, ATG8s) and substrate, acting as a molecular adaptor/scaffold.
Reason: Informative molecular function capturing TRIM5alpha's role as a selective-autophagy receptor/adaptor that links cargo to the autophagy apparatus.
Supporting Evidence:
PMID:25127057
act as platforms assembling ULK1 and Beclin 1 in their
GO:0160247 autophagy cargo adaptor activity
IPI
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
NEW
Summary: TRIM5alpha acts as a selective-autophagy cargo adaptor/receptor that recognizes viral capsid cargo and couples it to autophagic degradation.
Reason: PN showed that the accepted GO:0030674 adaptor annotation can be made more precise with existing GO:0160247. This is an upgrade to an existing GO term, not a new term request.
Supporting Evidence:
PMID:25127057
TRIM5Ξ± acts as a selective autophagy receptor
PMID:25127057
TRIM5Ξ± delivered its cognate cytosolic target, a viral capsid protein, for autophagic degradation
GO:0032880 regulation of protein localization
IMP
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
KEEP AS NON CORE
Summary: Mutant-phenotype evidence that TRIM5alpha regulates localization of autophagy components/cargo.
Reason: Supported but a broad process term reflecting the autophagy-platform role.
Supporting Evidence:
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic substrates by direct recognition
GO:1990462 omegasome
IDA
PMID:25127057
TRIM proteins regulate autophagy and can target autophagic s...
ACCEPT
Summary: Colocalization with the omegasome (autophagosome-formation site), consistent with TRIM5alpha's autophagy-platform role.
Reason: Experimentally supported colocalization at autophagosome biogenesis sites, consistent with the autophagy function.
Supporting Evidence:
PMID:25127057
act as platforms assembling ULK1 and Beclin 1 in their
GO:0005829 cytosol
TAS
Reactome:R-HSA-1031716
ACCEPT
Summary: Reactome curation of cytosolic localization in the interferon-gamma-stimulated gene context.
Reason: Correct cytosolic localization, consistent with the core cytoplasmic site of action.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IDA
PMID:23077300
TRIM protein-mediated regulation of inflammatory and innate ...
ACCEPT
Summary: Direct evidence (TRIM-family NF-kB activation screen) that TRIM5 positively regulates NF-kB signaling via TAK1.
Reason: Core biological process; TRIM5-driven TAK1 activation induces NF-kB.
Supporting Evidence:
PMID:23077300
to induce NF-ΞΊB and MAP kinase (MAPK) signaling
GO:0005737 cytoplasm
IDA
PMID:18248090
TRIM E3 ligases interfere with early and late stages of the ...
ACCEPT
Summary: Direct evidence of cytoplasmic localization in the retroviral restriction screen. Core localization.
Reason: Correct core localization, experimentally demonstrated.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Predominantly localizes in cytoplasmic bodies
GO:0005515 protein binding
IPI
PMID:20357094
p62/sequestosome-1 associates with and sustains the expressi...
KEEP AS NON CORE
Summary: Interaction with SQSTM1/p62 that sustains TRIM5alpha expression. Bare protein binding is uninformative.
Reason: Records a real, functionally relevant SQSTM1 interaction but bare protein binding is uninformative.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Interacts with SQSTM1
GO:0005515 protein binding
IPI
PMID:22078707
TRIM5alpha associates with proteasomal subunits in cells whi...
KEEP AS NON CORE
Summary: Interaction with proteasome subunit PSMC2 (and other proteasome subunits) in cytoplasmic bodies. Bare protein binding is uninformative.
Reason: Records a real proteasome-subunit interaction relevant to TRIM5 turnover/restriction but bare protein binding is uninformative.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Interacts with PSMC2
GO:0051607 defense response to virus
TAS
PMID:22291694
TRIM5alpha and Species Tropism of HIV/SIV.
ACCEPT
Summary: Author-statement (review) that TRIM5alpha defends against retroviruses. Core process.
Reason: Core biological process; TRIM5alpha is a retroviral restriction factor.
Supporting Evidence:
PMID:22291694
TRIM5Ξ± recognizes the multimerized capsid proteins (viral core) of an incoming virus by its PRYSPRY domain
GO:0002218 activation of innate immune response
IDA
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Direct evidence that capsid-lattice sensing by TRIM5 activates the innate immune response. Core process.
Reason: Core biological process; capsid recognition triggers TRIM5 ligase activity and innate immune signaling.
Supporting Evidence:
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid lattice
GO:0004842 ubiquitin-protein transferase activity
IDA
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Direct evidence that capsid binding triggers TRIM5 E3 ubiquitin transferase activity (with UBE2V1-UBE2N). Core MF.
Reason: Core molecular function; TRIM5 catalyzes ubiquitin transfer to generate K63-linked chains upon capsid sensing.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Binding to the viral capsid triggers its E3 ubiquitin ligase activity
GO:0005515 protein binding
IPI
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
KEEP AS NON CORE
Summary: Interactions with the TAK1 complex (MAP3K7, TAB2, TAB3) from the innate-sensor study. Bare protein binding is uninformative.
Reason: Records real, functionally central interactions (TAK1 complex) but bare protein binding is uninformative.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
MAP3K7/TAK1, TAB2 and TAB3
GO:0031664 regulation of lipopolysaccharide-mediated signaling pathway
IMP
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
KEEP AS NON CORE
Summary: Mutant-phenotype evidence linking TRIM5-mediated TAK1 activation to LPS/innate signaling pathways.
Reason: Supported but a specific signaling-context process; the core mechanism is capsid-triggered TAK1/NF-kB activation. Defer to curator.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
autophosphorylation of the MAP3K7/TAK1 complex
GO:0038187 pattern recognition receptor activity
IDA
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Direct evidence that TRIM5 acts as a pattern recognition receptor for the retroviral capsid lattice. Core molecular function.
Reason: Core molecular function; TRIM5 is a cytosolic PRR sensing the capsid lattice PAMP.
Supporting Evidence:
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid lattice
GO:0043123 positive regulation of canonical NF-kappaB signal transduction
IMP
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Mutant-phenotype evidence that TRIM5 positively regulates NF-kB signaling. Core process.
Reason: Core biological process; redundant with the IDA/IBA NF-kB annotations.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Activation of the MAP3K7/TAK1 complex by autophosphorylation
GO:0043410 positive regulation of MAPK cascade
IMP
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Mutant-phenotype evidence that TRIM5-mediated TAK1 activation positively regulates the MAPK cascade. Core process.
Reason: Core biological process; capsid-triggered TAK1 activation induces MAPK-responsive genes.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
autophosphorylation of the MAP3K7/TAK1 complex
GO:0051607 defense response to virus
TAS
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Author-statement that TRIM5 defends against retroviruses. Core process.
Reason: Core biological process; redundant with the antiviral/restriction annotations.
Supporting Evidence:
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid lattice
GO:0070534 protein K63-linked ubiquitination
IDA
PMID:21512573
TRIM5 is an innate immune sensor for the retrovirus capsid l...
ACCEPT
Summary: Direct evidence that TRIM5, with UBE2V1-UBE2N, generates K63-linked polyubiquitin chains. Core activity.
Reason: Core biological process; the K63-chain synthesis is the mechanistic link between capsid sensing and TAK1/NF-kB activation.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
generates 'Lys-63'-linked
GO:0042803 protein homodimerization activity
IPI
PMID:11331580
The tripartite motif family identifies cell compartments.
ACCEPT
Summary: Self-association reported in the foundational TRIM-family paper; homodimerization/multimerization essential for restriction. Core MF.
Reason: Core molecular function; self-multimerization underlies capsid-lattice avidity and restriction.
Supporting Evidence:
file:human/TRIM5/TRIM5-uniprot.txt
Can form homodimers and homotrimers

Core Functions

Acts as a capsid-specific retroviral restriction factor and pattern-recognition receptor; the C-terminal B30.2/PRYSPRY domain directly recognizes the assembled retroviral capsid lattice, blocking infection at an early post-entry step and triggering downstream signaling.

Supporting Evidence:
  • PMID:21512573
    TRIM5 is an innate immune sensor for the retrovirus capsid lattice
  • PMID:22291694
    TRIM5Ξ± recognizes the multimerized capsid proteins (viral core) of an incoming virus by its PRYSPRY domain

Functions as a RING-type E3 ubiquitin ligase that, upon capsid sensing and together with UBE2V1-UBE2N, synthesizes Lys63-linked polyubiquitin chains to activate the TAK1 (MAP3K7)-TAB2-TAB3 kinase complex and drive NF-kB and MAPK/AP-1 innate immune signaling.

Supporting Evidence:
  • file:human/TRIM5/TRIM5-uniprot.txt
    Binding to the viral capsid triggers its E3 ubiquitin ligase activity
  • PMID:21512573
    TRIM5 is an innate immune sensor for the retrovirus capsid lattice

Acts in selective ("precision") autophagy as a receptor/adaptor that directly recognizes the HIV-1 capsid protein and delivers it for autophagic degradation, and as a platform that assembles and activates ULK1 and Beclin-1.

Directly Involved In:
Cellular Locations:
Supporting Evidence:

Self-multimerizes (homodimers/homotrimers via the coiled-coil and B-box) to achieve the avidity required for capsid-lattice recognition and restriction.

Cellular Locations:
Supporting Evidence:
  • file:human/TRIM5/TRIM5-uniprot.txt
    Can form homodimers and homotrimers

References

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Suggested Questions for Experts

Q: How is the balance between TRIM5alpha's two effector outcomes after capsid recognition - proteasome-dependent restriction versus selective autophagic delivery of the capsid - controlled in a given cell type?

Q: To what extent does the innate immune signaling (PRR/TAK1/NF-kB) function of TRIM5alpha contribute to antiviral protection in vivo independently of direct capsid restriction?

Suggested Experiments

Experiment: Reconstitute capsid-triggered TRIM5alpha E3 ligase activity in vitro with purified TRIM5alpha (wild-type vs RING C15A and PRYSPRY mutants), UBE2V1-UBE2N, ubiquitin and assembled capsid tubes, to map how lattice binding stimulates unanchored K63-chain synthesis and TAK1 activation.

Experiment: Use separation-of-function TRIM5alpha mutants (restriction-competent/signaling-dead and signaling-competent/restriction-dead) in primary human cells to dissect the relative contributions of capsid restriction, NF-kB/MAPK signaling, and selective autophagy to antiretroviral defense.

πŸ“š Additional Documentation

Notes

(TRIM5-notes.md)

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Pn Notes

(TRIM5-pn-notes.md)

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πŸ“„ View Raw YAML

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