| 2004 |
TRIM5α (a component of cytoplasmic bodies) restricts HIV-1 infection in Old World monkey cells at a post-entry, pre-reverse transcription step; the block is species-specific, acts on the incoming viral capsid, and is relieved by TRIM5α knockdown. |
siRNA knockdown, retroviral infectivity assays, subcellular localization by immunofluorescence |
Nature |
High |
14985764
|
| 2004 |
TRIM5α restricts both HIV-1 and N-tropic murine leukemia virus (N-MLV), indicating broader antiretroviral specificity determined by the viral capsid; human, rhesus, and African green monkey TRIM5α variants show different but overlapping restriction spectra. |
Overexpression of TRIM5α orthologs in permissive cells, retroviral infectivity assays with capsid mutants |
Proceedings of the National Academy of Sciences of the United States of America |
High |
15249685 15249687 15249690
|
| 2004 |
In owl monkeys, a LINE-1 retrotransposon-mediated insertion of a CypA cDNA into the TRIM5 locus creates a TRIM5-CypA fusion protein (TRIMCyp) that restricts HIV-1 through CypA-dependent capsid recognition; this fusion accounts for post-entry HIV-1 restriction in owl monkey cells. |
RNAi knockdown, cDNA cloning, transfer of TRIMCyp to human/rat cells, cyclosporin A inhibition assays |
Nature |
High |
15243629 15326303
|
| 2006 |
TRIM5α orthologs from Old World monkeys specifically associate with the HIV-1 capsid via the B30.2 domain; this interaction promotes rapid, premature capsid disassembly (accelerated uncoating) as shown by loss of particulate capsid and gain of soluble capsid protein. Proteasome inhibition does not abrogate restriction. |
Capsid binding assays, quantification of particulate vs. soluble capsid after infection, proteasome inhibitor treatment |
Proceedings of the National Academy of Sciences of the United States of America |
High |
16540544
|
| 2006 |
Human TRIM5α mediates accelerated uncoating (premature conversion of particulate to soluble capsid) of N-MLV in a capsid residue 110-dependent manner; domains required for potent restriction are also required for capsid disassembly. |
Quantification of particulate vs. soluble MLV capsid in infected cells, domain deletion mutants, capsid residue 110 mutants |
Journal of virology |
High |
17135314
|
| 2006 |
TRIM5α is rapidly turned over (half-life ~50–60 min) via polyubiquitylation dependent on intact RING and B-box 2 domains; proteasome inhibition triggers aggresome formation containing TRIM5α, polyubiquitylated proteins, heat shock proteins, and dynein. |
Pulse-chase half-life assays, domain mutant analysis, proteasome inhibitor treatment, immunofluorescence co-localization |
Virology |
High |
16472833
|
| 2006 |
Proteasome inhibition of TRIM5α-restricted cells allows reverse transcription products to accumulate even though infection remains blocked, indicating TRIM5α restricts retroviral infection at multiple steps; pre-integration complexes generated under proteasome inhibition are competent for integration in vitro. |
Proteasome inhibitor treatment, quantitative PCR for reverse transcription products, in vitro integration assay |
Journal of virology |
High |
16973579
|
| 2005 |
TRIM5α oligomerizes into trimers; the coiled-coil and B30.2(SPRY) domains contribute to trimer formation/stability. A RING/B-box 2-deleted dominant-negative TRIM5α forms heterotrimers with wild-type TRIM5α, explaining the dominant-negative effect. |
Analytical ultracentrifugation, co-immunoprecipitation, gel filtration, dominant-negative assays |
Journal of virology |
Medium |
16254380
|
| 2008 |
Recombinant TRIM5α (TRIM5-21R chimera) is predominantly dimeric; it has E3 ubiquitin ligase activity (auto-ubiquitylation with multiple E2 enzymes in vitro) and directly binds HIV-1 CA-NC assemblies via the SPRY domain V1 loop without other mammalian proteins. |
Analytical ultracentrifugation, in vitro ubiquitylation assay, direct capsid binding assay with purified recombinant protein |
Journal of virology |
High |
18799573
|
| 2008 |
TRIM5α functions as a RING-finger E3 ubiquitin ligase in vitro and in vivo, auto-ubiquitinates in cooperation with UbcH5B, is also ubiquitinated by Ro52 (another E3 ligase), and deubiquitinated by Yersinia effector YopJ. Monoubiquitination of TRIM5α signals its translocation from cytoplasmic bodies to the cytoplasm. |
In vitro ubiquitylation assay, overexpression/co-IP, monoubiquitin-fusion assay, confocal microscopy |
The FEBS journal |
Medium |
18312418
|
| 2008 |
Encounter with a restriction-sensitive retroviral core causes rapid proteasome-dependent degradation of TRIM5α; this occurs specifically with restrictive TRIM5α-capsid pairs (rhesus TRIM5α with HIV-1, human TRIM5α with N-MLV, TRIMCyp with HIV-1) and is prevented by proteasome inhibitors or CsA. |
Western blot of TRIM5α levels after virus inoculation, proteasome inhibitor treatment, CsA treatment, endogenous TRIM5α measurement in rhesus cells |
PLoS pathogens |
High |
18497858
|
| 2009 |
The TRIM5α B-box 2 domain has an unusual hydrophobic surface patch (cluster 1) and flanking Arg121 that are required for higher-order self-association and avid capsid binding, which are the major mechanisms by which B-box 2 potentiates HIV-1 restriction (not turnover or cytoplasmic body formation). |
NMR structure of B-box 2 domain, site-directed mutagenesis, capsid binding assays, higher-order oligomerization assays, retroviral infectivity assays |
Journal of virology |
High |
19656869
|
| 2010 |
Recombinant TRIM5α spontaneously assembles into two-dimensional paracrystalline hexagonal lattices; assembly requires protein dimerization and B-box 2 Arg121 but not the SPRY domain. Assembly is promoted by binding to hexagonal CA arrays, suggesting a deformable hexagonal scaffold model for retroviral capsid recognition. |
Electron microscopy of 2D crystalline arrays, mutagenesis, capsid array-templated assembly assay |
Proceedings of the National Academy of Sciences of the United States of America |
High |
21187419
|
| 2011 |
TRIM5 is a RING domain E3 ubiquitin ligase that, acting with UBC13-UEV1A, catalyses synthesis of unattached K63-linked ubiquitin chains to activate TAK1 kinase and stimulate AP-1 and NF-κB innate immune signalling; interaction with the retroviral capsid lattice greatly enhances UBC13-UEV1A-dependent E3 activity; TAK1 and UBC13 contribute to capsid-specific restriction. |
In vitro ubiquitin chain synthesis assay, TAK1/UBC13 knockdown, NF-κB/AP-1 reporter assays, virus challenge experiments |
Nature |
High |
21512573
|
| 2011 |
Rhesus TRIM5α disrupts the HIV-1 capsid specifically at inter-hexamer interfaces; CC-SPRY domain binds CA assemblies in a concentration-dependent manner and releases protofilament fragments of CA hexamers without dissociating into monomers. Intra-hexamer crosslinking does not prevent disruption, but inter-hexamer crosslinking does. |
CryoEM of CA assemblies incubated with purified TRIM5α fragments, chemical crosslinking with disulfide bond-forming CA mutants |
PLoS pathogens |
High |
21455494
|
| 2011 |
The RING domain of TRIM5α has E3 ubiquitin ligase activity; RING domain residues in the E2-binding region are required for both self-ubiquitylation and potent HIV-1 restriction, demonstrating that E3 ligase activity contributes to restriction. The NMR structure of the TRIM5α RING domain was determined. |
NMR structure determination, site-directed mutagenesis of RING domain, in vitro self-ubiquitylation assay, retroviral infectivity assay |
Journal of virology |
High |
21734049
|
| 2012 |
Crystal structure of the rhesus TRIM5α PRY/SPRY domain reveals that capsid binding is mediated by flexible hypervariable loops (including the mobile v1 segment) that map to the structurally divergent face, paralleling antigen recognition by IgM antibodies; the monomeric PRY/SPRY alone can bind HIV-1 CA assemblies. |
X-ray crystallography of PRY/SPRY domain, biochemical capsid binding assay, cryoEM |
Proceedings of the National Academy of Sciences of the United States of America |
High |
22847415 23091002
|
| 2005 |
CypA is required for HIV-1 restriction by Old World monkey TRIM5α: CypA knockdown increases HIV-1 infectivity to the same extent as TRIM5 knockdown; CsA and CA mutations that disrupt CypA binding rescue HIV-1 from restriction; simultaneous CypA and TRIM5 knockdown causes no additional increase in titer, placing CypA upstream of TRIM5α. |
RNAi knockdown of CypA and TRIM5 (separately and combined), CsA treatment, CA mutant viruses, epistasis analysis |
Proceedings of the National Academy of Sciences of the United States of America |
High |
16203999
|
| 2005 |
TRIM5α orthologs form heteromultimers via their conserved coiled-coil domains; non-human primate TRIM5α expressed in human cells can disrupt the anti-N-MLV activity of endogenous human TRIM5α through heteromultimerization, not through the C-terminal capsid-recognition domain. |
Co-immunoprecipitation, dominant-negative assays, co-localization, domain deletion analysis |
Journal of virology |
Medium |
15919943
|
| 2007 |
TRIM5α cytoplasmic bodies are highly dynamic structures: they move along microtubules (saltatory and long-distance), undergo morphological changes, and TRIM5α protein rapidly exchanges between cytoplasmic bodies and diffuse cytoplasmic pools. Association with cytoplasmic bodies is not required for antiretroviral activity. |
Live-cell fluorescence microscopy, FRAP, photoactivation, microtubule perturbation |
Molecular biology of the cell |
High |
17392513
|
| 2005 |
Cytoplasmic body association is not required for TRIM5α antiretroviral activity: spider monkey TRIM5α restricts retroviruses without forming cytoplasmic bodies; geldanamycin (Hsp90 inhibitor) dissolves cytoplasmic bodies without affecting restriction. |
Overexpression of TRIM5α orthologs (GFP fusion), geldanamycin treatment, retroviral infectivity assays |
Virology |
Medium |
16183097
|
| 2005 |
TRIM5α transcription is upregulated by interferons (IFN-α and IFN-β) through an ISRE element in the TRIM5α promoter; STAT1 binds to the ISRE sequence; IFN-β induces TRIM5α protein expression. |
Northern blot, qRT-PCR, luciferase reporter assay, EMSA, Western blot with specific antibody |
Biochemical and biophysical research communications |
Medium |
16289103
|
| 2008 |
A second, independently generated TRIM5-CypA fusion (TRIMCyp) exists in pigtailed macaques; its distinct HIV-1 restriction specificity is explained by a point mutation near the CypA:capsid-binding interface acquired during/after transposition. |
Genomic sequencing, functional infectivity assays, CsA inhibition, site-directed mutagenesis of CypA interface |
Proceedings of the National Academy of Sciences of the United States of America |
High |
18287034 18389077
|
| 2010 |
When MLV infection is restricted by human TRIM5α, integrase protein and reverse transcription products are lost from cells while capsid and viral RNA are solubilized; proteasome inhibition blocks these biochemical consequences but not antiviral potency, indicating proteasomes are required for TRIM5α-induced core disruption but not restriction per se. |
Sucrose gradient fractionation of retroviral core components after synchronized infection, proteasome inhibitor treatment, quantitative detection of CA, integrase, viral RNA, and RT products |
PLoS pathogens |
High |
23505372
|
| 2015 |
TRIM5α employs E2 enzyme Ube2W to anchor K63-linked polyubiquitin chains via TRIM5α auto-ubiquitination; Ube2W monoubiquitinates TRIM5α at internal lysines (especially K45 and K50), which serves as a substrate for chain elongation by Ube2N/Ube2V2; depletion of these E2 enzymes or ubiquitin mutation inhibits restriction-associated reverse transcription block. |
In vitro ubiquitination reconstitution, E2 depletion by siRNA, Ub mutant analysis, MS identification of modified lysines |
The EMBO journal |
High |
26101372
|
| 2015 |
RING dimerization of TRIM5α is required for activation of Ubc13 (K63-linkage-specific E2) to synthesize K63-linked polyubiquitin chains; higher-order oligomerization (promoted by capsid interaction) enhances RING dimerization and therefore E3 ligase activity. |
Crystal structure of TRIM5α RING:Ubc13-Ub complex, analytical ultracentrifugation, mutagenesis, in vitro ubiquitination assay |
Cell reports |
High |
26212332
|
| 2016 |
Crystal structure of the TRIM5α B-box 2 domain shows it can form both dimers and trimers; trimers link multiple TRIM5α proteins into a hexagonal net matching capsid lattice spacing. B-box-mediated interactions also sterically restrict RING domain dimerization, modulating E3 ligase activity. |
X-ray crystallography, functional mutagenesis, capsid binding and restriction assays |
eLife |
High |
27253059
|
| 2016 |
Human TRIM5α restricts HIV-1 in Langerhans cells (LCs) but not in subepithelial DC-SIGN+ DCs; restriction depends on HIV-1 binding to Langerin (C-type lectin), which routes HIV-1 into a TRIM5α-mediated autophagy-activating pathway; DC-SIGN binding causes TRIM5α to dissociate and abrogates restriction. |
siRNA knockdown of TRIM5α in primary DCs, co-IP of TRIM5α with Langerin/DC-SIGN, autophagy inhibitor assays, confocal microscopy, retroviral infectivity assays in primary cells |
Nature |
High |
27919079
|
| 2018 |
Hexagonal assembly of TRIM5 on retroviral capsids triggers N-terminal polyubiquitination; trivalent RING arrangement enables elongation of N-terminally anchored K63-linked ubiquitin chains (N-K63-Ub). N-K63-Ub drives innate immune stimulation and proteasomal degradation of TRIM5; premature ubiquitination before lattice assembly triggers degradation and ablates restriction. |
Ubiquitin chain analysis by MS, Ub mutant TRIM5α constructs, inducible ubiquitination system, innate immune reporter assays, retroviral infectivity assays |
Cell host & microbe |
High |
30503508
|
| 2019 |
CypA shields HIV-1 from restriction by human TRIM5α in primary human blood cells; disruption of the CA-CypA interaction renders HIV-1 susceptible to potent human TRIM5α restriction before reverse transcription; endogenous TRIM5α associates with virion cores entering the cytoplasm only when the CA-CypA interaction is disrupted. |
CRISPR/CAS9 knockout and siRNA knockdown of TRIM5α in primary cells, CA-CypA mutant viruses, CsA treatment, co-fractionation of TRIM5α with incoming cores |
Nature microbiology |
High |
31636416
|
| 2019 |
Immunoproteasome activation (by IFN-α) reprograms human TRIM5α for effective capsid-dependent HIV-1 restriction; the immunoproteasome accelerates TRIM5α turnover, and this is required for the switch to potent anti-HIV-1 activity; restriction is dependent on viral capsid. |
siRNA library screen in IFN-α-treated cells, siRNA/CRISPR knockdown of immunoproteasome subunits, HIV-1 infectivity assays, TRIM5α stability measurements |
Nature microbiology |
High |
30886358
|
| 2014 |
TRIM5α acts as a selective autophagy receptor for HIV-1; it recognizes and targets HIV-1 for autophagic destruction and nucleates the core autophagy machinery by assembling ULK1 and BECN1 into an active complex; TRIM5α interactions with mammalian Atg8 proteins are required for this anti-HIV effector function. |
Co-IP of TRIM5α with autophagy components, knockdown of autophagic mediators, retroviral infectivity assays, protein interaction mapping |
Autophagy |
Medium |
25587751
|
| 2016 |
Autophagic degradation of TRIM5α occurs basally (LC3b and LAMP2A co-localize with TRIM5α bodies); however, depletion of ATG5, Beclin1, or p62 by siRNA or CRISPR does not abrogate retroviral restriction by human TRIM5α, rhesus TRIM5α, or TRIMCyp, indicating autophagy is not required for restriction. |
siRNA and CRISPR-Cas9 depletion of autophagy mediators, retroviral infectivity assays, immunofluorescence co-localization, lysosomal inhibitor treatment |
Journal of virology |
High |
26764007
|
| 2010 |
Human TRIM5α affects TAB2 protein levels, abrogating TAB2-dependent NF-κB activation; human and rhesus TRIM5α also activate NF-κB reporter expression in a dose-dependent manner; distinct TRIM5α domains mediate TAB2 level effects, NF-κB activation, and capsid recognition independently. |
Co-immunoprecipitation, Western blot for TAB2 levels, NF-κB reporter assay, domain deletion/swap analysis |
Virology |
Medium |
21035162
|
| 2011 |
SUMO-interacting motifs (SIMs) in the TRIM5α B30.2 domain are required for its anti-N-MLV activity; SUMO-1 overexpression blocks N-MLV infection in a TRIM5α-dependent manner; SUMO conjugation of the MLV capsid CA is also required for TRIM5α restriction, suggesting TRIM5α binds SUMO-conjugated CA via its SIMs. |
SUMO-1 overexpression, TRIM5α knockdown rescue, SIM mutagenesis, Ub/SUMO conjugation site mutation of CA, retroviral infectivity assays |
PLoS pathogens |
Medium |
21490953
|
| 2010 |
p62/sequestosome-1 co-localizes with TRIM5α cytoplasmic bodies, closely associates with TRIM5α as shown by FRET, and sustains TRIM5α protein expression and cytoplasmic body number; p62 knockdown reduces TRIM5α-mediated retroviral restriction in both overexpressing and endogenous TRIM5α-expressing cells. |
Co-IP, FRET analysis, siRNA knockdown of p62, retroviral infectivity assays, immunofluorescence |
Journal of virology |
Medium |
20357094
|
| 2015 |
Among seven primate and carnivore TRIM5 orthologs, all activate AP-1 innate immune signaling, and this activation is TAK1-dependent and required for retroviral restriction activity; mouse Trim12 (but not Trim30) paralogs also show this correlation when fused to CypA. |
AP-1 reporter assays, TAK1 inhibition, TRIMCyp fusion proteins, retroviral infectivity assays with panel of TRIM5 orthologs |
Journal of virology |
Medium |
26468522
|
| 2015 |
In dendritic cells (DCs), endogenous TRIM5α accumulates in nuclear bodies in a SUMOylation-dependent manner, preventing cytoplasmic retroviral restriction but enabling cGAS-mediated type I IFN sensing of incoming reverse-transcribed DNA. Inhibiting SUMOylation (ginkgolic acid) redistributes TRIM5α to the cytoplasm, restoring restriction but abolishing IFN production. |
Immunofluorescence localization of endogenous TRIM5α, SUMOylation inhibitor treatment, cGAS reporter assays, retroviral infectivity assays, primary DC isolation |
Cell reports |
High |
26748714
|
| 2019 |
Both human and rhesus TRIM5α restrict specific flaviviruses (tick-borne encephalitis complex) by binding to the viral NS2B/3 protease via the SPRY domain, promoting K48-linked ubiquitination of NS2B/3 and its proteasomal degradation; mosquito-borne flaviviruses (dengue, Zika, yellow fever) are resistant. |
Co-IP of TRIM5α with NS2B/3, ubiquitination assays, proteasome inhibitor rescue, retroviral infectivity assays, TRIM5α knockdown |
Cell reports |
High |
31189110
|
| 2020 |
Human TRIM5α senses and restricts LINE-1 retroelements; TRIM5α interacts with LINE-1 ribonucleoprotein complexes in the cytoplasm (required for restriction) and induces AP-1 and NF-κB innate immune signaling upon LINE-1 interaction, leading to down-regulation of LINE-1 promoter activity. |
Co-IP of TRIM5α with LINE-1 RNP complexes, LINE-1 retrotransposition reporter assays, siRNA knockdown, AP-1/NF-κB reporter assays |
Proceedings of the National Academy of Sciences of the United States of America |
Medium |
32651277
|
| 2020 |
TRIM5α self-assembles into hexagonal lattices on HIV-1 capsid; constrained diffusion allows lattice reorganization; defects form on highly curved capsid surfaces to alleviate strain; the TRIM5α binding interface on CA is localized near the CypA-binding loop by statistical analysis of simulation data. |
Coarse-grained molecular dynamics simulations validated by electron cryo-tomography imaging |
Nature communications |
Medium |
32161265
|
| 2018 |
TRIM5α binding to HIV-1 capsid induces global rigidification of the capsid assembly and perturbs key inter-molecular interfaces essential for higher-order capsid assembly, with structural and dynamic changes throughout the entire CA polypeptide; this suggests TRIM5α uses allosteric mechanisms to destabilize the capsid lattice. |
Magic-angle spinning NMR of assembled capsid with and without TRIM5α, molecular dynamics simulations |
Proceedings of the National Academy of Sciences of the United States of America |
High |
30333189
|
| 2022 |
Pandemic HIV-1(M) has evolved two specific capsid amino acid adaptations that prevent TRIM5 (and cGAS) triggering in myeloid cells; genetic reversal of these adaptations restores TRIM5-mediated antiviral responses; structural analysis by X-ray crystallography identified the capsid differences. |
Phylogenetic analysis, X-ray crystallography of HIV capsid variants, retroviral replication assays in myeloid cells, innate immune reporter assays with capsid point mutants |
Nature microbiology |
High |
36289397
|
| 2023 |
TRIM5α restricts orthopoxviruses by binding to the orthopoxvirus capsid protein L3 via its SPRY domain, promoting innate immune activation; vaccinia virus protein C6 antagonizes TRIM5α by binding to its RING domain and inducing proteasome-dependent degradation; CypA is recruited to poxvirus factories via L3 interaction and antagonizes TRIM5α; CsA (by inhibiting CypA) restores TRIM5α-mediated poxvirus restriction. |
Co-IP of TRIM5α with L3 and C6, proteasome inhibitor rescue of TRIM5α levels, TRIM5α knockout/knockdown infectivity assays, CsA treatment, cyclosporine derivative antiviral activity assays |
Nature |
High |
37558876
|
| 2010 |
TRIM5α directly disrupts the structure of preassembled HIV-1 CA-NC cylindrical complexes in vitro; this disruption is correlated with restriction specificity (rhesus TRIM5α and TRIMCyp disrupt; human TRIM5α and TRIMCyp blocked by CsA do not). |
Electron microscopy of CA-NC assemblies incubated with cell lysates expressing TRIM5 proteins, CsA inhibition |
Journal of virology |
Medium |
20410272
|
| 2011 |
TRIM5α modulates isoforms: alternatively spliced TRIM5 isoforms lacking the SPRY domain (TRIM5ι, γ, δ, κ) act as dominant negatives against TRIM5α; specific knockdown of TRIM5ι increases TRIM5α antiviral activity, indicating that endogenous truncated isoforms physiologically reduce TRIM5α function in human cells. |
Isoform-specific siRNA knockdown, retroviral infectivity assays, qRT-PCR quantification of isoform ratios |
Journal of virology |
Medium |
21632761
|
| 2010 |
The coiled-coil domain of TRIM5α, in addition to mediating oligomerization, conditions the spectrum of antiretroviral specificity; three specific coiled-coil residues (one under positive selection in primates) influence restriction specificity, cooperating with the PRYSPRY domain to determine capsid capture. |
Chimeric TRIM5α constructs between human and squirrel monkey, site-directed mutagenesis of coiled-coil residues, retroviral infectivity assays |
Journal of virology |
Medium |
20219908
|