Affinage

TRAF3IP3

TRAF3-interacting JNK-activating modulator · UniProt Q9Y228

Length
551 aa
Mass
63.6 kDa
Annotated
2026-06-10
19 papers in source corpus 10 papers cited in narrative 10 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 7/7 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

TRAF3IP3 (T3JAM) is a multi-compartment adapter protein that couples organelle-specific scaffolding to immune signaling, T cell development, and cell-fate decisions (PMID:26195727, PMID:31390091). It was first defined as a TRAF3-specific binding partner that recruits TRAF3 to a detergent-insoluble fraction and selectively drives JNK rather than NF-κB activation (PMID:14572659). In the secretory pathway TRAF3IP3 localizes to the Golgi/trans-Golgi network, where it recruits MEK and promotes its interaction with BRAF to enable TCR-stimulated ERK activation during thymocyte positive selection and NKT2 maturation; a constitutively active MEK transgene rescues the T cell development block in knockout mice (PMID:26195727, PMID:31076725). At the lysosome it recruits the phosphatase catalytic subunit PP2Ac to engage the mTORC1 component Raptor, thereby restraining mTORC1-driven glycolysis and stabilizing regulatory T cells (PMID:30115741). In antiviral innate immunity TRAF3IP3 has dual, compartment-dependent roles: it accumulates on mitochondria upon viral infection to bridge TRAF3 to MAVS and license TBK1-IRF3-driven interferon production (PMID:31390091), while also interacting with TRAF3 and TBK1 to direct DTX4-dependent K48-linked ubiquitination of TBK1 at K372, limiting excess type I interferon in myeloid cells (PMID:32366851). TRAF3IP3 additionally regulates autophagic pathways, promoting autophagy via an ATG16L1-binding motif to sustain marginal zone B cell survival (PMID:26011558) and blocking mitophagy by promoting NEDD4 degradation in cardiomyocytes (PMID:39240426). Through its transmembrane domain it recruits STRN3 to the ER to trigger PERK/ATF4/CHOP-mediated ER stress and apoptosis in lung adenocarcinoma cells (PMID:40068093).

Mechanistic history

Synthesis pass · year-by-year structured walk · 10 steps
  1. 2003 Medium

    Established TRAF3IP3 as a TRAF-selective adapter, answering whether it engages the TRAF family broadly or specifically and which downstream pathway it routes to.

    Evidence Co-IP across TRAF family members, subcellular fractionation, and JNK/NF-κB reporter assays in overexpression systems

    PMID:14572659

    Open questions at the time
    • Endogenous TRAF3 association not shown
    • Physiological cell context and stimulus undefined
    • Structural basis of TRAF3 specificity unknown
  2. 2015 High

    Resolved a developmental function by placing TRAF3IP3 at the Golgi as the scaffold that couples MEK to BRAF for TCR-driven ERK signaling during thymocyte positive selection.

    Evidence Conditional knockout mice, subcellular localization, MEK-BRAF co-IP, and genetic rescue with constitutively active MEK

    PMID:26195727

    Open questions at the time
    • How TRAF3IP3 is targeted to the Golgi not defined
    • Direct vs. indirect MEK binding interface unmapped
  3. 2015 Medium

    Identified an autophagy-promoting role via an ATG16L1-binding motif, linking TRAF3IP3 to marginal zone B cell survival.

    Evidence Knockout mice, autophagy and apoptosis assays, and mutational analysis of the ATG16L1-binding motif

    PMID:26011558

    Open questions at the time
    • Direct ATG16L1 binding via the motif not biochemically confirmed
    • Subcellular site of this interaction undefined
  4. 2018 High

    Defined a lysosomal, metabolism-restraining function: TRAF3IP3 recruits PP2Ac to dephosphorylate the mTORC1 component Raptor and limit glycolysis in Tregs.

    Evidence Treg-specific conditional knockout, lysosomal fractionation, PP2Ac-Raptor co-IP, and metabolic/mTORC1 activity assays

    PMID:30115741

    Open questions at the time
    • Mechanism of lysosomal targeting unclear
    • Whether Raptor is the direct PP2Ac dephosphorylation substrate not demonstrated enzymatically
  5. 2019 High

    Established a positive antiviral role by showing mitochondrial TRAF3IP3 bridges TRAF3 to MAVS to drive TBK1-IRF3 interferon responses.

    Evidence Knockout mice, virus infection assays, TRAF3-MAVS co-IP, and mitochondrial localization linked to IFN output

    PMID:31390091

    Open questions at the time
    • Trigger for mitochondrial accumulation undefined
    • Direct binding topology among TRAF3IP3/TRAF3/MAVS unmapped
  6. 2019 Medium

    Extended the Golgi-MEK-ERK axis to NKT2 cell maturation, generalizing the trans-Golgi scaffolding role beyond conventional thymocytes.

    Evidence T-cell-specific conditional knockout, trans-Golgi localization, MEK1 co-IP, and ERK phosphorylation/nuclear translocation assays

    PMID:31076725

    Open questions at the time
    • Single lab
    • Direct MEK1 binding interface not mapped
  7. 2020 High

    Revealed an opposing, negative-feedback function in myeloid cells: TRAF3IP3 promotes DTX4-dependent K48 ubiquitination of TBK1 at K372 to restrain excess IFN-I.

    Evidence Myeloid-specific conditional knockout, TRAF3/TBK1 co-IP, ubiquitination site mapping, and DTX4 genetic epistasis

    PMID:32366851

    Open questions at the time
    • How cell-type context switches TRAF3IP3 between pro- and anti-IFN roles unresolved
    • Whether the same molecular pool performs both functions unknown
  8. 2022 Medium

    Characterized TRAF3IP3 as a restriction factor cleaved by enterovirus 3C protease and identified functional NLS/NES elements governing its antiviral activity.

    Evidence Yeast two-hybrid, co-IP, immunofluorescence, cleavage site mapping (87Q-88G), and NLS/NES functional analysis in Jurkat and RD cells

    PMID:35814660

    Open questions at the time
    • Nuclear function of TRAF3IP3 not mechanistically defined
    • Relationship between nuclear shuttling and organelle-based roles unclear
  9. 2024 Medium

    Showed TRAF3IP3 blocks mitophagy by promoting NEDD4 degradation, worsening myocardial ischemia-reperfusion injury.

    Evidence Co-IP, cycloheximide chase, knockdown in H9C2 cells, and an in vivo I/R rat model

    PMID:39240426

    Open questions at the time
    • Mechanism by which TRAF3IP3 promotes NEDD4 turnover not defined
    • Link from NEDD4 loss to mitophagy block not fully mapped
  10. 2025 Medium

    Identified an ER-localized, pro-apoptotic function: TRAF3IP3 uses its transmembrane domain to recruit STRN3 and trigger PERK/ATF4/CHOP ER stress in lung adenocarcinoma.

    Evidence IP-MS, co-IP, transmembrane domain mutagenesis, STRN3 knockdown rescue, and apoptosis/viability assays

    PMID:40068093

    Open questions at the time
    • Direct STRN3 binding interface beyond TM dependence unmapped
    • How ER targeting is coordinated with other organelle pools unknown

Open questions

Synthesis pass · forward-looking unresolved questions
  • It remains unresolved how a single adapter is partitioned among Golgi, lysosome, mitochondria, ER, and nucleus, and what governs its context-dependent switching between opposing functions (pro- vs. anti-interferon; autophagy vs. mitophagy).
  • No structural model defines distinct organelle-targeting determinants
  • No single study compares multiple compartmental pools in one cell type
  • Direct binding interfaces for most partners (MEK, MAVS, PP2Ac, STRN3) unmapped

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 4 GO:0098772 molecular function regulator activity 2
Localization
GO:0005794 Golgi apparatus 2 GO:0005634 nucleus 1 GO:0005739 mitochondrion 1 GO:0005764 lysosome 1 GO:0005783 endoplasmic reticulum 1
Pathway
R-HSA-162582 Signal Transduction 3 R-HSA-168256 Immune System 3 R-HSA-1266738 Developmental Biology 2 R-HSA-9612973 Autophagy 2 R-HSA-5357801 Programmed Cell Death 1

Evidence

Reading pass · 10 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2003 T3JAM (TRAF3IP3) was identified as a novel protein that specifically associates with TRAF3 but not other TRAF family members. Co-expression of T3JAM with TRAF3 recruits TRAF3 to the detergent-insoluble fraction, and T3JAM and TRAF3 synergistically activate JNK but not NF-κB, indicating T3JAM functions as an adapter molecule specifically regulating TRAF3-mediated JNK activation. Co-immunoprecipitation, subcellular fractionation, overexpression reporter assays for JNK and NF-κB activation FEBS letters Medium 14572659
2015 TRAF3IP3 localizes to the Golgi and is required for TCR-stimulated ERK and MEK activation during thymocyte positive selection. Mechanistically, TRAF3IP3 recruits MEK to the Golgi, facilitating the interaction of MEK with its activator BRAF. Transgenic expression of constitutively active MEK rescues the T cell development block in Traf3ip3 knockout mice. Conditional knockout mice, T cell development assays, subcellular fractionation/localization, co-immunoprecipitation, genetic rescue with constitutively active MEK The Journal of experimental medicine High 26195727
2015 TRAF3IP3 promotes autophagy via an ATG16L1-binding motif. Loss of TRAF3IP3 in knockout mice leads to diminished autophagy and increased apoptosis in marginal zone B cells, impairing their survival and resulting in defective T-independent type II immune responses. Knockout mice, autophagy assays, apoptosis assays, mutational analysis of ATG16L1-binding motif Clinical and experimental immunology Medium 26011558
2018 Lysosomal TRAF3IP3 restricts mTORC1 signaling in regulatory T cells by recruiting the serine-threonine phosphatase catalytic subunit PP2Ac to the lysosome, thereby facilitating the interaction of PP2Ac with the mTORC1 component Raptor. Loss of TRAF3IP3 causes hyper-glycolytic metabolism via excessive mTORC1 activity, destabilizing Treg cells. T reg-specific conditional knockout mice, co-immunoprecipitation of PP2Ac-Raptor interaction, lysosomal fractionation/localization, metabolic assays, mTORC1 activity measurements The Journal of experimental medicine High 30115741
2019 TRAF3IP3 accumulates on mitochondria upon virus infection and mediates the recruitment of TRAF3 to MAVS, thereby facilitating TBK1-IRF3 activation for interferon production. Traf3ip3-deficient mice show severely compromised interferon production and increased susceptibility to RNA virus infection. Knockout mice, virus infection assays, co-immunoprecipitation, mitochondrial localization assays, interferon production measurements The EMBO journal High 31390091
2019 TRAF3IP3 at the trans-Golgi network recruits MEK1 and facilitates ERK phosphorylation and nuclear translocation in NKT2 cells, promoting their functional maturation. T-cell-specific deletion of TRAF3IP3 reduces thymic NKT2 cells and impairs IL-4 production. T-cell-specific conditional knockout mice, trans-Golgi network localization assays, co-immunoprecipitation of MEK1, ERK phosphorylation and nuclear translocation assays Cellular & molecular immunology Medium 31076725
2020 TRAF3IP3 suppresses cytosolic RNA-triggered IFN-I production by interacting with endogenous TRAF3 and TBK1, leading to K48-linked (degradative) ubiquitination of TBK1 at its K372 residue in a DTX4-dependent fashion. Myeloid-specific deletion of Traf3ip3 increases RNA virus-triggered IFN-I production and reduces susceptibility to virus. Myeloid-specific conditional knockout mice, overexpression systems, co-immunoprecipitation of TRAF3 and TBK1, ubiquitination site mapping (K372), DTX4-dependence established by genetic manipulation, virus susceptibility assays Nature communications High 32366851
2022 TRAF3IP3 is cleaved by EV71 3C protease at the 87Q-88G site, which partially resists TRAF3IP3-mediated inhibition of EV71 replication. TRAF3IP3 possesses nuclear localization signal (NLS) and nuclear export signal (NES); the NES contributes to TRAF3IP3-mediated alteration of 3Cpro localization and inhibition of EV71 replication. Yeast two-hybrid, co-immunoprecipitation, immunofluorescence, cleavage site mapping, NLS/NES functional analysis, viral replication assays in Jurkat and RD cells Frontiers in microbiology Medium 35814660
2024 TRAF3IP3 blocks mitophagy to exacerbate myocardial ischemia-reperfusion injury by promoting the degradation of NEDD4 protein. Knockdown of TRAF3IP3 induces mitophagy and enhances mitochondrial function, alleviating myocardial injury in I/R rats. Co-immunoprecipitation, CHX (cycloheximide chase) assays, immunoblot, immunostaining, knockdown in H9C2 cells, in vivo I/R rat model Cardiovascular toxicology Medium 39240426
2025 TRAF3IP3 triggers ER stress via the PERK/ATF4/CHOP pathway in lung adenocarcinoma cells and facilitates recruitment of STRN3 to the ER lumen through its transmembrane domain. TRAF3IP3-induced ER stress-mediated apoptosis and cytoprotective autophagy are dependent on STRN3, identified by IP-MS as a direct downstream interactor. IP-MS identification of STRN3 as binding partner, co-immunoprecipitation, transmembrane domain mutational analysis, ER stress pathway analysis (PERK/ATF4/CHOP), STRN3 knockdown rescue experiments, cell viability/apoptosis assays Advanced science Medium 40068093

Source papers

Stage 0 corpus · 19 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2018 Metabolic control of regulatory T cell stability and function by TRAF3IP3 at the lysosome. The Journal of experimental medicine 60 30115741
2020 TRAF3IP3 negatively regulates cytosolic RNA induced anti-viral signaling by promoting TBK1 K48 ubiquitination. Nature communications 48 32366851
2019 TRAF3IP3 mediates the recruitment of TRAF3 to MAVS for antiviral innate immunity. The EMBO journal 46 31390091
2003 T3JAM, a novel protein that specifically interacts with TRAF3 and promotes the activation of JNK(1). FEBS letters 38 14572659
2015 T cell development involves TRAF3IP3-mediated ERK signaling in the Golgi. The Journal of experimental medicine 37 26195727
2015 TRAF3IP3, a novel autophagy up-regulated gene, is involved in marginal zone B lymphocyte development and survival. Clinical and experimental immunology 29 26011558
2021 Alpinia oxyphylla Miq extract reduces cerebral infarction by downregulating JNK-mediated TLR4/T3JAM- and ASK1-related inflammatory signaling in the acute phase of transient focal cerebral ischemia in rats. Chinese medicine 14 34419138
2022 TRAF3IP3 Is Cleaved by EV71 3C Protease and Exhibits Antiviral Activity. Frontiers in microbiology 12 35814660
2019 TRAF3IP3 at the trans-Golgi network regulates NKT2 maturation via the MEK/ERK signaling pathway. Cellular & molecular immunology 10 31076725
2025 TRAF3IP3 Induces ER Stress-Mediated Apoptosis with Protective Autophagy to Inhibit Lung Adenocarcinoma Proliferation. Advanced science (Weinheim, Baden-Wurttemberg, Germany) 9 40068093
2024 Neuroprotective effects of Gastrodia elata Blume on promoting M2 microglial polarization by inhibiting JNK/TLR4/T3JAM/NF-κB signaling after transient ischemic stroke in rats. Frontiers in pharmacology 8 39391701
2022 TRAF3IP3 promotes glioma progression through the ERK signaling pathway. Frontiers in oncology 7 36185204
2021 Novel germline TRAF3IP3 mutation in a dyad with familial acute B lymphoblastic leukemia. Cancer reports (Hoboken, N.J.) 6 33503336
2024 SNORA5A regulates tumor-associated macrophage M1/M2 phenotypes via TRAF3IP3 in breast cancer. Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas 3 39166607
2024 TRAF3IP3 Blocks Mitophagy to Exacerbate Myocardial Injury Induced by Ischemia-Reperfusion. Cardiovascular toxicology 3 39240426
2022 The variants in PTPRB, TRAF3IP3, and DISC1 genes were associated with Graves' disease in the Chinese population. Medicine 1 36397361
2013 [Cloning and eukaryotic expression of human TRAF3IP3 gene]. Xi bao yu fen zi mian yi xue za zhi = Chinese journal of cellular and molecular immunology 1 23643262
2025 TRAF3IP3::FGFR1: a novel FGFR1 fusion identified in an aggressive case of acute myeloid leukemia. Annals of hematology 0 40590913
2024 Targeting inhibition of T3JAM reduces brain cell ferroptosis in rat following ischemia/reperfusion via a mechanism involving prevention of TLR4-mediated iron overload. Archives of biochemistry and biophysics 0 39581339

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