TRAPPC5 is the human Trs31 ortholog and a small TRAPP core subunit. It supports TRAPP complex architecture, complex-level RAB1 guanine-nucleotide exchange, and ER-to-Golgi vesicle-mediated transport. Autophagy-related effects are best understood through TRAPP/TRAPPII/TRAPPIII complex membership and ER-Golgi trafficking rather than an independent TRAPPC5-specific autophagy function.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:1990071 TRAPPII protein complex | IBA GO_REF:0000033 | ACCEPT | Summary: TRAPPC5 is represented in TRAPPII protein complex through the shared TRAPP core. Reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core subunit. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:27066478 TRAPP II, which contains core TRAPP plus TrappC9-10, and TRAPP III, which contains core TRAPP plus TrappC8, 11-13 Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:1990072 TRAPPIII protein complex | IBA GO_REF:0000033 | ACCEPT | Summary: TRAPPC5 is represented in TRAPPIII protein complex through the shared TRAPP core. Reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core subunit. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:27066478 TRAPP II, which contains core TRAPP plus TrappC9-10, and TRAPP III, which contains core TRAPP plus TrappC8, 11-13 Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0006888 endoplasmic reticulum to Golgi vesicle-mediated transport | IBA GO_REF:0000033 | ACCEPT | Summary: TRAPPC5 contributes to TRAPP-dependent ER-to-Golgi trafficking. Reason: Accept as a core process. TRAPPC5 is a core TRAPP subunit, and TRAPP complex/RAB1 biology supports ER-to-Golgi vesicle-mediated transport. Supporting Evidence: PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it |
| GO:1990070 TRAPPI protein complex | IBA GO_REF:0000033 | MARK AS OVER ANNOTATED | Summary: TRAPPI protein complex is problematic as a human TRAPPC5 annotation. Reason: Mark as over-annotated. TRAPPC5 is a yeast TRAPP I core ortholog, but the mammalian literature questions the existence of a discrete TRAPP I complex in vivo. Supporting Evidence: PMID:21525244 absence of a TRAPP I-equivalent complex in mammalian cells PMID:27066478 TRAPP I cannot be separated from the mammalian TRAPP II and its existence in vivo in mammalian cells is currently in question PMID:27066478 there is currently no evidence for the existence of TRAPP I in mammalian cells |
| GO:0005783 endoplasmic reticulum | IEA GO_REF:0000044 | ACCEPT | Summary: endoplasmic reticulum localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. ORGANELLES check (2026-11-06): the IEA maps the UniProt location "Endoplasmic reticulum {ECO:0000250}", a by-similarity line with no named source (UniProt places yeast Trs31p, Q03337, at the cis-Golgi network and ER). The claim holds by complex membership: TRAPPC5 is a core TRAPP subunit with TRAPPC3, whose endogenous mammalian ortholog is concentrated on Sec31p-marked transitional ER (ER exit sites) by immuno-EM (PMID:16880271), and the TRAPPC12 paper summarises that TRAPPC3 localizes to the transitional ER (PMID:21525244). No assay places TRAPPC5 itself at the ER. It is a soluble peripheral subunit with no TM segment or signal peptide, so the ER pool is on the cytosolic face; with only the complex-membership line, no ER exit site, membrane or lumen row is added (TRAPPC3 carries the NEW ER exit site row). Kept ACCEPT because TRAPPC5 is an obligate TRAPP core subunit and the complex's GEF and tethering activity is exercised at the ER exit site (PMID:16880271), which is why core_functions also names the ER. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic PMID:21525244 C3, a core component of the complex, localizes to the transitional ER PMID:16880271 Immuno-EM in NRK cells confirmed that mBet3p (5-nm gold particles) resides on the tER region labeled with Sec31p (10-nm gold particles). |
| GO:0005794 Golgi apparatus | IEA GO_REF:0000044 | ACCEPT | Summary: Golgi apparatus localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic |
| GO:0030008 TRAPP complex | IEA GO_REF:0000120 | ACCEPT | Summary: TRAPPC5 is a human TRAPP core subunit. Reason: Accept as core cellular-component membership. Mammalian TRAPP component work identifies C5/TRAPPC5 among known human TRAPP components. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:21525244 known human TRAPP components, including C3, C4, and C5 PMID:27066478 A single TRAPP complex purified from mammalian cell lysate contains all the known subunits |
| GO:0048193 Golgi vesicle transport | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Golgi vesicle transport is plausible TRAPP context but less specific than ER-to-Golgi transport for TRAPPC5. Reason: Keep as non-core. The core process is ER-to-Golgi/TRAPP/RAB1 transport; broader Golgi vesicle transport is a reasonable parent/context but not the most specific function. Supporting Evidence: PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic |
| GO:0005515 protein binding | IPI PMID:25416956 A proteome-scale map of the human interactome network. | MARK AS OVER ANNOTATED | Summary: Generic protein binding is not informative for TRAPPC5 function. Reason: Mark as over-annotated. Proteome-scale interactions and TRAPP-subunit interactions should be interpreted through TRAPP complex membership, not generic protein binding. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 |
| GO:0005515 protein binding | IPI PMID:28514442 Architecture of the human interactome defines protein commun... | MARK AS OVER ANNOTATED | Summary: Generic protein binding is not informative for TRAPPC5 function. Reason: Mark as over-annotated. Proteome-scale interactions and TRAPP-subunit interactions should be interpreted through TRAPP complex membership, not generic protein binding. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 |
| GO:0005515 protein binding | IPI PMID:31515488 Extensive disruption of protein interactions by genetic vari... | MARK AS OVER ANNOTATED | Summary: Generic protein binding is not informative for TRAPPC5 function. Reason: Mark as over-annotated. Proteome-scale interactions and TRAPP-subunit interactions should be interpreted through TRAPP complex membership, not generic protein binding. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 |
| GO:0005515 protein binding | IPI PMID:32296183 A reference map of the human binary protein interactome. | MARK AS OVER ANNOTATED | Summary: Generic protein binding is not informative for TRAPPC5 function. Reason: Mark as over-annotated. Proteome-scale interactions and TRAPP-subunit interactions should be interpreted through TRAPP complex membership, not generic protein binding. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 |
| GO:0005515 protein binding | IPI PMID:33961781 Dual proteome-scale networks reveal cell-specific remodeling... | MARK AS OVER ANNOTATED | Summary: Generic protein binding is not informative for TRAPPC5 function. Reason: Mark as over-annotated. Proteome-scale interactions and TRAPP-subunit interactions should be interpreted through TRAPP complex membership, not generic protein binding. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 |
| GO:0005737 cytoplasm | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | ACCEPT | Summary: cytoplasm localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: PMID:21525244 known human TRAPP components, including C3, C4, and C5 Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic |
| GO:0006888 endoplasmic reticulum to Golgi vesicle-mediated transport | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | ACCEPT | Summary: TRAPPC5 contributes to TRAPP-dependent ER-to-Golgi trafficking. Reason: Accept as a core process. TRAPPC5 is a core TRAPP subunit, and TRAPP complex/RAB1 biology supports ER-to-Golgi vesicle-mediated transport. Supporting Evidence: PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it |
| GO:0006901 vesicle coat assembly | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | MODIFY | Summary: vesicle coat assembly overstates TRAPPC5 as a coat-assembly factor. Reason: Modify to ER-to-Golgi vesicle-mediated transport. TRAPPC5 participates in TRAPP-dependent trafficking, but the evidence does not show direct coat assembly by TRAPPC5. Proposed replacements: endoplasmic reticulum to Golgi vesicle-mediated transport Supporting Evidence: PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 TRAPPCII is recruited to ER-derived vesicles by virtue of an interaction between the TRAPPCII component TRAPPC3 and the COPII coat protein SEC23 |
| GO:0048208 COPII vesicle coat assembly | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | MODIFY | Summary: COPII vesicle coat assembly overstates TRAPPC5 as a coat-assembly factor. Reason: Modify to ER-to-Golgi vesicle-mediated transport. TRAPPC5 participates in TRAPP-dependent trafficking, but the evidence does not show direct coat assembly by TRAPPC5. Proposed replacements: endoplasmic reticulum to Golgi vesicle-mediated transport Supporting Evidence: PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 TRAPPCII is recruited to ER-derived vesicles by virtue of an interaction between the TRAPPCII component TRAPPC3 and the COPII coat protein SEC23 |
| GO:0099022 obsolete vesicle tethering | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | MODIFY | Summary: The obsolete vesicle-tethering annotation should not be kept as-is for TRAPPC5. Reason: Modify to ER-to-Golgi vesicle-mediated transport, the supported TRAPPC5/TRAPP process. Mammalian TRAPP tethering remains unresolved and the term is obsolete. Proposed replacements: endoplasmic reticulum to Golgi vesicle-mediated transport Supporting Evidence: PMID:27066478 evidence that any TRAPP complex acts as a membrane tether is currently inconclusive PMID:21525244 in ER-to-Golgi trafficking at a very early stage Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic |
| GO:1990071 TRAPPII protein complex | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | ACCEPT | Summary: TRAPPC5 is represented in TRAPPII protein complex through the shared TRAPP core. Reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core subunit. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:27066478 TRAPP II, which contains core TRAPP plus TrappC9-10, and TRAPP III, which contains core TRAPP plus TrappC8, 11-13 Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:1990072 TRAPPIII protein complex | NAS PMID:27066478 TRAPP Complexes in Secretion and Autophagy. | ACCEPT | Summary: TRAPPC5 is represented in TRAPPIII protein complex through the shared TRAPP core. Reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core subunit. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:27066478 TRAPP II, which contains core TRAPP plus TrappC9-10, and TRAPP III, which contains core TRAPP plus TrappC8, 11-13 Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0030008 TRAPP complex | IDA PMID:21525244 C4orf41 and TTC-15 are mammalian TRAPP components with a rol... | ACCEPT | Summary: TRAPPC5 is a human TRAPP core subunit. Reason: Accept as core cellular-component membership. Mammalian TRAPP component work identifies C5/TRAPPC5 among known human TRAPP components. Supporting Evidence: PMID:21525244 with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b PMID:21525244 known human TRAPP components, including C3, C4, and C5 PMID:27066478 A single TRAPP complex purified from mammalian cell lysate contains all the known subunits |
| GO:0005829 cytosol | TAS Reactome:R-HSA-5694409 | ACCEPT | Summary: cytosol localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0005829 cytosol | TAS Reactome:R-HSA-5694418 | ACCEPT | Summary: cytosol localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0005829 cytosol | TAS Reactome:R-HSA-5694439 | ACCEPT | Summary: cytosol localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0005829 cytosol | TAS Reactome:R-HSA-5694441 | ACCEPT | Summary: cytosol localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
| GO:0005829 cytosol | TAS Reactome:R-HSA-8877475 | ACCEPT | Summary: cytosol localization is consistent with TRAPPC5 as a soluble/peripheral TRAPP trafficking subunit. Reason: Accept as a supported location for TRAPPC5-containing TRAPP reactions. Supporting Evidence: Reactome:R-HSA-5694409 The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it Reactome:R-HSA-5694439 TRAPPC is a multi-subunit tethering complex that facilitates ER-to-Golgi traffic Reactome:R-HSA-8877475 RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III |
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Download this section (compressed HTML)Q: Should TRAPPC5 receive a contributes_to RAB1 guanine-nucleotide exchange factor activity annotation based on Trs31-dependent yeast GEF evidence plus mammalian TRAPP complex models?
Suggested experts: GO transport editors, Reactome TRAPP curators
Q: Should human TRAPPI protein complex annotations be removed or replaced when the literature questions a discrete mammalian TRAPP I complex?
Suggested experts: GO cellular-component editors, ComplexPortal curators
Q: Should PN TRAPP-component autophagy context be represented only by TRAPPIII membership for TRAPPC5 unless TRAPPC5-specific autophagy experiments are available?
Suggested experts: GO autophagy editors, TRAPP biology experts
Experiment: Reconstitute TRAPPC5-containing human TRAPP complexes and measure RAB1 GDP-GTP exchange after TRAPPC5 depletion or interface mutation.
Hypothesis: TRAPPC5 is required as a core TRAPP subunit for complex-level RAB1 GEF activity.
Type: complex reconstitution and RAB1 GEF assay
Experiment: Use TRAPPC5 knockout/rescue cells to assay ER-to-Golgi cargo transport, TRAPP complex stability, and Golgi/ER localization of TRAPP subunits.
Hypothesis: TRAPPC5 loss disrupts TRAPP-dependent ER-to-Golgi vesicle-mediated transport by destabilizing or mislocalizing the TRAPP core.
Type: cellular trafficking rescue assay
Experiment: Biochemically separate human TRAPPII and TRAPPIII pools containing TRAPPC5 and test whether any discrete TRAPPI-like pool exists in vivo.
Hypothesis: TRAPPC5 is present in human TRAPPII/TRAPPIII assemblies, while a discrete mammalian TRAPPI complex is absent or not stable in vivo.
Type: complex purification and native fractionation
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