TRAPPC5

UniProt ID: Q8IUR0
Organism: Homo sapiens
Review Status: COMPLETE
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Gene Description

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.

Existing Annotations Review

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.
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: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.
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.
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.
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

Core Functions

TRAPPC5 contributes the Trs31-like small core subunit to TRAPP complexes, supporting complex-level RAB1 guanine-nucleotide exchange and ER-to-Golgi trafficking. It should be modeled as contributing to the TRAPP complex activity rather than independently enabling GEF activity.

Directly Involved In:
endoplasmic reticulum to Golgi vesicle-mediated transport
Cellular Locations:
cytosol cytoplasm endoplasmic reticulum Golgi apparatus
In Complex:
TRAPP complex
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:21525244
    These activities are dependent on the subunits Bet3p, Trs31p, Trs23p, and Bet5p
  • Reactome:R-HSA-5694409
    The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it
  • Reactome:R-HSA-8877475
    RAB1 nucleotide exchange is stimulated in these pathways by the GEF activity of the multisubunit TRAPPC complexes II and III
  • 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

References

GO_REF:0000002
Gene Ontology annotation through association of InterPro records with GO terms
GO_REF:0000033
Annotation inferences using phylogenetic trees
GO_REF:0000044
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
GO_REF:0000120
Combined Automated Annotation using Multiple IEA Methods
PMID:21525244
C4orf41 and TTC-15 are mammalian TRAPP components with a role at an early stage in ER-to-Golgi trafficking.
PMID:25416956
A proteome-scale map of the human interactome network.
PMID:27066478
TRAPP Complexes in Secretion and Autophagy.
PMID:28514442
Architecture of the human interactome defines protein communities and disease networks.
PMID:31515488
Extensive disruption of protein interactions by genetic variants across the allele frequency spectrum in human populations.
PMID:32296183
A reference map of the human binary protein interactome.
PMID:33961781
Dual proteome-scale networks reveal cell-specific remodeling of the human interactome.
Reactome:R-HSA-5694409
Nucleotide exchange on RAB1
Reactome:R-HSA-5694418
RAB1:GTP binds USO1 and GORASP1:GOLGA2
Reactome:R-HSA-5694439
COPII coat binds TRAPPCII and RAB1:GDP
Reactome:R-HSA-5694441
CSNK1D phosphorylates SEC23
Reactome:R-HSA-8877475
TRAPPC complexes exchange GTP for GDP on RAB1

Suggested Questions for Experts

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

Suggested Experiments

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

📚 Additional Documentation

Notes

(TRAPPC5-notes.md)

TRAPPC5 notes

Review started from just fetch-gene human TRAPPC5. The proteostasis network places TRAPPC5 under Autophagy-Lysosome Pathway > Autophagophore initiation and elongation > Autophagy component recruitment to autophagophore > TRAPP complex component, the same PN leaf as TRAPPC1, TRAPPC3, and TRAPPC4.

Falcon deep research was requested with just deep-research-falcon human TRAPPC5, but the provider timed out after 600 seconds and did not produce TRAPPC5-deep-research-falcon.md. The review therefore relies on the cached UniProt, GOA, Reactome, publication, and PN context files listed here.

TRAPPC5 is the human ortholog of yeast Trs31 and a small TRAPP core subunit. UniProt says TRAPPC5 is a "Component of the multisubunit TRAPP (transport protein particle) complex" and may function in ER-to-Golgi vesicular transport. The mammalian TRAPP component paper states that yeast TRAPP I includes Trs31p, "with the mammalian orthologues named TRAPPC1, TRAPPC2, TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b" PMID:21525244. It also reports that C2/C2L purifications contained "known human TRAPP components, including C3, C4, and C5" PMID:21525244. Accept TRAPP complex membership and the ER-to-Golgi transport process.

TRAPPC5 should be modeled as contributing to complex-level RAB1 GEF activity rather than independently enabling a catalytic activity. The same mammalian TRAPP paper notes that yeast TRAPP GEF/tethering activities are dependent on Bet3p, Trs31p, Trs23p, and Bet5p PMID:21525244. Reactome states that "The TRAPPC complex acts as a guanine-nucleotide exchange factor for RAB1, activating it" [Reactome:R-HSA-5694409 "Nucleotide exchange on RAB1"] and that RAB1 exchange is stimulated by "the GEF activity of the multisubunit TRAPPC complexes II and III" [Reactome:R-HSA-8877475 "TRAPPC complexes exchange GTP for GDP on RAB1"].

The TRAPPI protein-complex annotation needs caution in human. PMID:21525244 says mammalian TRAPP differs from yeast and that their study supports the "absence of a TRAPP I-equivalent complex in mammalian cells" PMID:21525244. The TRAPP review similarly says "TRAPP I cannot be separated from the mammalian TRAPP II and its existence in vivo in mammalian cells is currently in question" and "there is currently no evidence for the existence of TRAPP I in mammalian cells" PMID:27066478. Therefore, mark human TRAPPI protein complex as over-annotated, but accept TRAPPII/TRAPPIII where ComplexPortal/Reactome support them.

The PN autophagy context should be represented through TRAPPIII/TRAPP membership unless TRAPPC5-specific autophagy evidence appears. The PN mapping rationale says the TRAPP component leaf is autophagy-contextual but that the shared gene-level semantics are captured by TRAPP complex membership [projects/PROTEOSTASIS/reports/pn_projection/pn_projected_annotations.tsv]. Reactome links TRAPPCIII/RAB1 to pre-autophagosomal structure biology, but TRAPPC5 itself has no seeded direct autophagy process annotation.

The coat-assembly and obsolete tethering annotations are likely over-specific. Reactome supports TRAPP/COPII/RAB1 recruitment on ER-derived vesicles, but TRAPPC5 is not a COPII coat-assembly factor. The TRAPP review states that "evidence that any TRAPP complex acts as a membrane tether is currently inconclusive" PMID:27066478. Modify vesicle coat assembly, COPII vesicle coat assembly, and obsolete vesicle tethering to ER-to-Golgi vesicle-mediated transport.

Generic protein binding annotations from proteome-scale interactome sources are not informative for TRAPPC5. Specific interactions with TRAPPC3, TRAPPC2, CCNDBP1, or HMG20A are better captured as TRAPP complex membership or left as non-core interaction context, not as a core molecular function.

Annotation stance:
- Core: TRAPP complex membership, TRAPPII/TRAPPIII complex membership, contributes-to TRAPP complex RAB1 GEF activity, ER-to-Golgi vesicle-mediated transport, cytoplasm/cytosol, ER, and Golgi apparatus.
- Non-core: broad Golgi vesicle transport.
- Modify: vesicle coat assembly, COPII vesicle coat assembly, and obsolete vesicle tethering to ER-to-Golgi vesicle-mediated transport.
- Mark over-annotated: human TRAPPI protein complex and generic protein binding rows.

Description cleanup note

The YAML description field was revised to keep it as a standalone biological summary. Project-specific curation framing moved here instead.

  • Moved out of the YAML description: the prior wording described the TRAPP-component context as PN-specific and interpreted TRAPPC5 through TRAPP/TRAPPII/TRAPPIII complex membership and ER-Golgi trafficking rather than a broad autophagy process annotation.

Pn Notes

(TRAPPC5-pn-notes.md)

TRAPPC5 PN Consistency Notes

  • Generated: 2026-06-18
  • Project: PROTEOSTASIS
  • Scope: PN consistency rereview against local AIGR review and available deep-research artifacts
  • UniProt: Q8IUR0
  • AIGR review status: COMPLETE
  • Review batch: proteostasis-pr-1217 (PR 1217)
  • Batch change status: added

Source Files Checked

Deep Research Files

  • No *-deep-research*.md file found in this gene directory.

AIGR Review Snapshot

  • Description: 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.
  • Existing/core annotation action counts: ACCEPT: 16; KEEP_AS_NON_CORE: 1; MARK_AS_OVER_ANNOTATED: 6; MODIFY: 3

PN Consistency Summary

  • Consistency: Coherent. Notes, review, PN row ("TRAPP complex, core subunit"), and node mapping agree TRAPPC5 (Trs31 ortholog, small core subunit) acts via complex-level RAB1 GEF + ER-to-Golgi transport. Review carries GO:0030008 (IDA/IEA) and TRAPPII/TRAPPIII memberships. Notable, defensible deviation from raw GOA: the IBA GO:1990070 TRAPPI complex annotation is MARK_AS_OVER_ANNOTATED because mammalian TRAPP I existence is "in question" (PMID:21525244, PMID:27066478) — well argued, not a contradiction.
  • PN story / NEW pressure: PN Notes mention ATG9/ATG2 trafficking. Review keeps autophagy as TRAPPIII-membership context only; TRAPPC5 has no gene-specific autophagy evidence. Defensible. Conclusion: already captured via complex membership; no NEW term.
  • Evidence alignment: PN titles ("Membrane Trafficking in Autophagy"; PMID:27066478) both in review; review adds PMID:21525244 and Reactome. Generic protein-binding rows (PMID:25416956/28514442/31515488/32296183/33961781) over-annotated. No miscitation.
  • Verdict: Consistent; ACCEPT mapping. Includes a sound TRAPPI-overannotation call beyond the PN scope.

Full Consistency Review

  • UniProt: Q8IUR0 · batch: proteostasis-pr-1217 · review status: COMPLETE
  • PN placement: Autophagy-Lysosome Pathway|Autophagophore initiation and elongation|Autophagy component recruitment to autophagophore|TRAPP complex component ; PN-node mapping: type-leaf mapped, scope=ok_for_propagation_to_go, GO:0030008 TRAPP complex (already_in_goa_exact)
  • Consistency: Coherent. Notes, review, PN row ("TRAPP complex, core subunit"), and node mapping agree TRAPPC5 (Trs31 ortholog, small core subunit) acts via complex-level RAB1 GEF + ER-to-Golgi transport. Review carries GO:0030008 (IDA/IEA) and TRAPPII/TRAPPIII memberships. Notable, defensible deviation from raw GOA: the IBA GO:1990070 TRAPPI complex annotation is MARK_AS_OVER_ANNOTATED because mammalian TRAPP I existence is "in question" (PMID:21525244, PMID:27066478) — well argued, not a contradiction.
  • PN story / NEW pressure: PN Notes mention ATG9/ATG2 trafficking. Review keeps autophagy as TRAPPIII-membership context only; TRAPPC5 has no gene-specific autophagy evidence. Defensible. Conclusion: already captured via complex membership; no NEW term.
  • Mapping strategy: No change to node. Projected GO:0030008 (OLS-verified) already in GOA. One subtlety worth flagging: the review demotes TRAPPI (GO:1990070) as a mammalian artifact, but the PN node projects only the parent GO:0030008, so no conflict with the projection.
  • Evidence alignment: PN titles ("Membrane Trafficking in Autophagy"; PMID:27066478) both in review; review adds PMID:21525244 and Reactome. Generic protein-binding rows (PMID:25416956/28514442/31515488/32296183/33961781) over-annotated. No miscitation.
  • Verdict: Consistent; ACCEPT mapping. Includes a sound TRAPPI-overannotation call beyond the PN scope.
  • Recommended edits: None required.

PN Dossier Context

  • review_batch: proteostasis-pr-1217
  • review_yaml: genes/human/TRAPPC5/TRAPPC5-ai-review.yaml
  • PN workbook rows: 1

PN row 1: Autophagy-Lysosome Pathway | Autophagophore initiation and elongation | Autophagy component recruitment to autophagophore | TRAPP complex component

  • UniProt: Q8IUR0
  • In branches: ALP
  • Notes: TRAPP complex, core subunit. The TRAPP complex serves as a GEF for RAB1. Involved in ATG9 and ATG2 trafficking
  • PN references (titles):
    • Membrane Trafficking in Autophagy - ScienceDirect
    • Frontiers | TRAPP Complexes in Secretion and Autophagy | Cell and Developmental Biology (frontiersin.org)
  • PN-node mapping records (path + ancestors):
    • [type] Autophagy-Lysosome Pathway|Autophagophore initiation and elongation|Autophagy component recruitment to autophagophore|TRAPP complex component
      status=mapped scope=ok_for_propagation_to_go GO=[GO:0030008 TRAPP complex]
      rationale: This PN leaf is a curated component bucket for TRAPP subunits used in autophagophore recruitment. The matching GO cellular-component term is TRAPP complex, and the member genes already converge strongly on that assignment in existing GOA.
    • [group] Autophagy-Lysosome Pathway|Autophagophore initiation and elongation|Autophagy component recruitment to autophagophore
      status=no_mapping scope= GO=[]
      rationale: Reviewed as a broad PN taxonomy container. The descendants mix components, regulators, context labels, and mechanistic leaves, so propagation should come only from narrower curated nodes.
    • [class] Autophagy-Lysosome Pathway|Autophagophore initiation and elongation
      status=context_only scope=too_broad_to_propagate GO=[GO:0016236 macroautophagy]
      rationale: This class is a real macroautophagy context, but its descendants include core factors, component buckets, upstream modulators, localization roles, and residual categories. Projecting generic macroautophagy from this ancestor creates TRAPP-like overpropagation, so candidate GO annotations must come from narrower curated nodes.
    • [branch] Autophagy-Lysosome Pathway
      status=no_mapping scope= GO=[]
      rationale: Reviewed as the top-level PN branch. It is a project taxonomy umbrella rather than a direct GO assertion; all propagation must come from manually curated child nodes.

Projected GO annotations (1)

  • GO:0030008 TRAPP complex | scope=ok_for_propagation_to_go | goa_status=already_in_goa_exact | from=Autophagy-Lysosome Pathway|Autophagophore initiation and elongation|Autophagy component recruitment to autophagophore|TRAPP complex component

Note

This file is generated from the current PROTEOSTASIS phase-1 dossier and local gene-review artifacts. Edit the source review, PN mapping, or dossier rather than this generated note when correcting the underlying curation.

📄 View Raw YAML

 
id: Q8IUR0
gene_symbol: TRAPPC5
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: >-
  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.
existing_annotations:
- term:
    id: GO:1990071
    label: TRAPPII protein complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: TRAPPC5 is represented in TRAPPII protein complex through the
      shared TRAPP core.
    action: ACCEPT
    reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are
      modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core
      subunit.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    - Reactome:R-HSA-8877475
    supported_by:
    - &id001
      reference_id: PMID:21525244
      supporting_text: with the mammalian orthologues named TRAPPC1, TRAPPC2,
        TRAPPC3, TRAPPC4, TRAPPC5, and TRAPPC6a/b
    - &id002
      reference_id: PMID:27066478
      supporting_text: TRAPP II, which contains core TRAPP plus TrappC9-10, and
        TRAPP III, which contains core TRAPP plus TrappC8, 11-13
    - &id003
      reference_id: Reactome:R-HSA-8877475
      supporting_text: RAB1 nucleotide exchange is stimulated in these pathways
        by the GEF activity of the multisubunit TRAPPC complexes II and III
- term:
    id: GO:1990072
    label: TRAPPIII protein complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: TRAPPC5 is represented in TRAPPIII protein complex through the
      shared TRAPP core.
    action: ACCEPT
    reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are
      modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core
      subunit.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    - Reactome:R-HSA-8877475
    supported_by:
    - *id001
    - *id002
    - *id003
- term:
    id: GO:0006888
    label: endoplasmic reticulum to Golgi vesicle-mediated transport
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: TRAPPC5 contributes to TRAPP-dependent ER-to-Golgi trafficking.
    action: ACCEPT
    reason: Accept as a core process. TRAPPC5 is a core TRAPP subunit, and TRAPP
      complex/RAB1 biology supports ER-to-Golgi vesicle-mediated transport.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-5694409
    supported_by:
    - &id006
      reference_id: PMID:21525244
      supporting_text: in ER-to-Golgi trafficking at a very early stage
    - &id004
      reference_id: Reactome:R-HSA-5694439
      supporting_text: TRAPPC is a multi-subunit tethering complex that
        facilitates ER-to-Golgi traffic
    - &id007
      reference_id: Reactome:R-HSA-5694409
      supporting_text: The TRAPPC complex acts as a guanine-nucleotide exchange
        factor for RAB1, activating it
- term:
    id: GO:1990070
    label: TRAPPI protein complex
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: part_of
  review:
    summary: TRAPPI protein complex is problematic as a human TRAPPC5
      annotation.
    action: MARK_AS_OVER_ANNOTATED
    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.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    supported_by:
    - reference_id: PMID:21525244
      supporting_text: absence of a TRAPP I-equivalent complex in mammalian
        cells
    - reference_id: PMID:27066478
      supporting_text: TRAPP I cannot be separated from the mammalian TRAPP II
        and its existence in vivo in mammalian cells is currently in question
    - reference_id: PMID:27066478
      supporting_text: there is currently no evidence for the existence of TRAPP
        I in mammalian cells
- term:
    id: GO:0005783
    label: endoplasmic reticulum
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: endoplasmic reticulum localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    supported_by:
    - &id005
      reference_id: PMID:21525244
      supporting_text: known human TRAPP components, including C3, C4, and C5
    - *id004
- term:
    id: GO:0005794
    label: Golgi apparatus
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: Golgi apparatus localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    supported_by:
    - *id005
    - *id004
- term:
    id: GO:0030008
    label: TRAPP complex
  evidence_type: IEA
  original_reference_id: GO_REF:0000120
  qualifier: part_of
  review:
    summary: TRAPPC5 is a human TRAPP core subunit.
    action: ACCEPT
    reason: Accept as core cellular-component membership. Mammalian TRAPP
      component work identifies C5/TRAPPC5 among known human TRAPP components.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    supported_by:
    - *id001
    - *id005
    - &id010
      reference_id: PMID:27066478
      supporting_text: A single TRAPP complex purified from mammalian cell
        lysate contains all the known subunits
- term:
    id: GO:0048193
    label: Golgi vesicle transport
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  review:
    summary: Golgi vesicle transport is plausible TRAPP context but less
      specific than ER-to-Golgi transport for TRAPPC5.
    action: KEEP_AS_NON_CORE
    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.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    supported_by:
    - *id006
    - *id004
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:25416956
  qualifier: enables
  review:
    summary: Generic protein binding is not informative for TRAPPC5 function.
    action: MARK_AS_OVER_ANNOTATED
    reason: Mark as over-annotated. Proteome-scale interactions and
      TRAPP-subunit interactions should be interpreted through TRAPP complex
      membership, not generic protein binding.
    additional_reference_ids:
    - PMID:21525244
    supported_by:
    - *id005
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:28514442
  qualifier: enables
  review:
    summary: Generic protein binding is not informative for TRAPPC5 function.
    action: MARK_AS_OVER_ANNOTATED
    reason: Mark as over-annotated. Proteome-scale interactions and
      TRAPP-subunit interactions should be interpreted through TRAPP complex
      membership, not generic protein binding.
    additional_reference_ids:
    - PMID:21525244
    supported_by:
    - *id005
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:31515488
  qualifier: enables
  review:
    summary: Generic protein binding is not informative for TRAPPC5 function.
    action: MARK_AS_OVER_ANNOTATED
    reason: Mark as over-annotated. Proteome-scale interactions and
      TRAPP-subunit interactions should be interpreted through TRAPP complex
      membership, not generic protein binding.
    additional_reference_ids:
    - PMID:21525244
    supported_by:
    - *id005
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:32296183
  qualifier: enables
  review:
    summary: Generic protein binding is not informative for TRAPPC5 function.
    action: MARK_AS_OVER_ANNOTATED
    reason: Mark as over-annotated. Proteome-scale interactions and
      TRAPP-subunit interactions should be interpreted through TRAPP complex
      membership, not generic protein binding.
    additional_reference_ids:
    - PMID:21525244
    supported_by:
    - *id005
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:33961781
  qualifier: enables
  review:
    summary: Generic protein binding is not informative for TRAPPC5 function.
    action: MARK_AS_OVER_ANNOTATED
    reason: Mark as over-annotated. Proteome-scale interactions and
      TRAPP-subunit interactions should be interpreted through TRAPP complex
      membership, not generic protein binding.
    additional_reference_ids:
    - PMID:21525244
    supported_by:
    - *id005
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: located_in
  review:
    summary: cytoplasm localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    supported_by:
    - *id005
    - *id004
- term:
    id: GO:0006888
    label: endoplasmic reticulum to Golgi vesicle-mediated transport
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: involved_in
  review:
    summary: TRAPPC5 contributes to TRAPP-dependent ER-to-Golgi trafficking.
    action: ACCEPT
    reason: Accept as a core process. TRAPPC5 is a core TRAPP subunit, and TRAPP
      complex/RAB1 biology supports ER-to-Golgi vesicle-mediated transport.
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-5694409
    supported_by:
    - *id006
    - *id004
    - *id007
- term:
    id: GO:0006901
    label: vesicle coat assembly
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: involved_in
  review:
    summary: vesicle coat assembly overstates TRAPPC5 as a coat-assembly factor.
    action: MODIFY
    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_replacement_terms:
    - &id008
      id: GO:0006888
      label: endoplasmic reticulum to Golgi vesicle-mediated transport
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id006
    - *id004
    - &id009
      reference_id: Reactome:R-HSA-8877475
      supporting_text: TRAPPCII is recruited to ER-derived vesicles by virtue of
        an interaction between the TRAPPCII component TRAPPC3 and the COPII coat
        protein SEC23
- term:
    id: GO:0048208
    label: COPII vesicle coat assembly
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: involved_in
  review:
    summary: COPII vesicle coat assembly overstates TRAPPC5 as a coat-assembly
      factor.
    action: MODIFY
    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_replacement_terms:
    - *id008
    additional_reference_ids:
    - PMID:21525244
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id006
    - *id004
    - *id009
- term:
    id: GO:0099022
    label: obsolete vesicle tethering
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: involved_in
  review:
    summary: The obsolete vesicle-tethering annotation should not be kept as-is
      for TRAPPC5.
    action: MODIFY
    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_replacement_terms:
    - *id008
    additional_reference_ids:
    - PMID:27066478
    - PMID:21525244
    - Reactome:R-HSA-5694439
    supported_by:
    - reference_id: PMID:27066478
      supporting_text: evidence that any TRAPP complex acts as a membrane tether
        is currently inconclusive
    - *id006
    - *id004
- term:
    id: GO:1990071
    label: TRAPPII protein complex
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: part_of
  review:
    summary: TRAPPC5 is represented in TRAPPII protein complex through the
      shared TRAPP core.
    action: ACCEPT
    reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are
      modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core
      subunit.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    - Reactome:R-HSA-8877475
    supported_by:
    - *id001
    - *id002
    - *id003
- term:
    id: GO:1990072
    label: TRAPPIII protein complex
  evidence_type: NAS
  original_reference_id: PMID:27066478
  qualifier: part_of
  review:
    summary: TRAPPC5 is represented in TRAPPIII protein complex through the
      shared TRAPP core.
    action: ACCEPT
    reason: Accept as complex-context membership. Human TRAPPII/TRAPPIII are
      modeled as core TRAPP plus accessory subunits, and TRAPPC5 is a small core
      subunit.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    - Reactome:R-HSA-8877475
    supported_by:
    - *id001
    - *id002
    - *id003
- term:
    id: GO:0030008
    label: TRAPP complex
  evidence_type: IDA
  original_reference_id: PMID:21525244
  qualifier: part_of
  review:
    summary: TRAPPC5 is a human TRAPP core subunit.
    action: ACCEPT
    reason: Accept as core cellular-component membership. Mammalian TRAPP
      component work identifies C5/TRAPPC5 among known human TRAPP components.
    additional_reference_ids:
    - PMID:21525244
    - PMID:27066478
    supported_by:
    - *id001
    - *id005
    - *id010
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-5694409
  qualifier: located_in
  review:
    summary: cytosol localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - Reactome:R-HSA-5694409
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id007
    - *id004
    - *id003
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-5694418
  qualifier: located_in
  review:
    summary: cytosol localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - Reactome:R-HSA-5694409
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id007
    - *id004
    - *id003
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-5694439
  qualifier: located_in
  review:
    summary: cytosol localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - Reactome:R-HSA-5694409
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id007
    - *id004
    - *id003
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-5694441
  qualifier: located_in
  review:
    summary: cytosol localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - Reactome:R-HSA-5694409
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id007
    - *id004
    - *id003
- term:
    id: GO:0005829
    label: cytosol
  evidence_type: TAS
  original_reference_id: Reactome:R-HSA-8877475
  qualifier: located_in
  review:
    summary: cytosol localization is consistent with TRAPPC5 as a
      soluble/peripheral TRAPP trafficking subunit.
    action: ACCEPT
    reason: Accept as a supported location for TRAPPC5-containing TRAPP
      reactions.
    additional_reference_ids:
    - Reactome:R-HSA-5694409
    - Reactome:R-HSA-5694439
    - Reactome:R-HSA-8877475
    supported_by:
    - *id007
    - *id004
    - *id003
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with
    GO terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular
    Location vocabulary mapping, accompanied by conservative changes to GO terms
    applied by UniProt
  findings: []
- id: GO_REF:0000120
  title: Combined Automated Annotation using Multiple IEA Methods
  findings: []
- id: PMID:21525244
  title: C4orf41 and TTC-15 are mammalian TRAPP components with a role at an
    early stage in ER-to-Golgi trafficking.
  findings: []
- id: PMID:25416956
  title: A proteome-scale map of the human interactome network.
  findings: []
- id: PMID:27066478
  title: TRAPP Complexes in Secretion and Autophagy.
  findings: []
- id: PMID:28514442
  title: Architecture of the human interactome defines protein communities and
    disease networks.
  findings: []
- id: PMID:31515488
  title: Extensive disruption of protein interactions by genetic variants across
    the allele frequency spectrum in human populations.
  findings: []
- id: PMID:32296183
  title: A reference map of the human binary protein interactome.
  findings: []
- id: PMID:33961781
  title: Dual proteome-scale networks reveal cell-specific remodeling of the
    human interactome.
  findings: []
- id: Reactome:R-HSA-5694409
  title: Nucleotide exchange on RAB1
  findings: []
- id: Reactome:R-HSA-5694418
  title: RAB1:GTP binds USO1 and GORASP1:GOLGA2
  findings: []
- id: Reactome:R-HSA-5694439
  title: COPII coat binds TRAPPCII and RAB1:GDP
  findings: []
- id: Reactome:R-HSA-5694441
  title: CSNK1D phosphorylates SEC23
  findings: []
- id: Reactome:R-HSA-8877475
  title: TRAPPC complexes exchange GTP for GDP on RAB1
  findings: []
core_functions:
- contributes_to_molecular_function:
    id: GO:0005085
    label: guanyl-nucleotide exchange factor activity
  in_complex:
    id: GO:0030008
    label: TRAPP complex
  description: TRAPPC5 contributes the Trs31-like small core subunit to TRAPP
    complexes, supporting complex-level RAB1 guanine-nucleotide exchange and
    ER-to-Golgi trafficking. It should be modeled as contributing to the TRAPP
    complex activity rather than independently enabling GEF activity.
  directly_involved_in:
  - id: GO:0006888
    label: endoplasmic reticulum to Golgi vesicle-mediated transport
  locations:
  - id: GO:0005829
    label: cytosol
  - id: GO:0005737
    label: cytoplasm
  - id: GO:0005783
    label: endoplasmic reticulum
  - id: GO:0005794
    label: Golgi apparatus
  supported_by:
  - *id001
  - *id005
  - reference_id: PMID:21525244
    supporting_text: These activities are dependent on the subunits Bet3p,
      Trs31p, Trs23p, and Bet5p
  - *id007
  - *id003
  - *id006
  - *id004
proposed_new_terms: []
suggested_questions:
- question: 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?
  experts:
  - GO transport editors
  - Reactome TRAPP curators
- question: Should human TRAPPI protein complex annotations be removed or
    replaced when the literature questions a discrete mammalian TRAPP I complex?
  experts:
  - GO cellular-component editors
  - ComplexPortal curators
- question: Should PN TRAPP-component autophagy context be represented only by
    TRAPPIII membership for TRAPPC5 unless TRAPPC5-specific autophagy
    experiments are available?
  experts:
  - GO autophagy editors
  - TRAPP biology experts
suggested_experiments:
- description: Reconstitute TRAPPC5-containing human TRAPP complexes and measure
    RAB1 GDP-GTP exchange after TRAPPC5 depletion or interface mutation.
  experiment_type: complex reconstitution and RAB1 GEF assay
  hypothesis: TRAPPC5 is required as a core TRAPP subunit for complex-level RAB1
    GEF activity.
- description: Use TRAPPC5 knockout/rescue cells to assay ER-to-Golgi cargo
    transport, TRAPP complex stability, and Golgi/ER localization of TRAPP
    subunits.
  experiment_type: cellular trafficking rescue assay
  hypothesis: TRAPPC5 loss disrupts TRAPP-dependent ER-to-Golgi vesicle-mediated
    transport by destabilizing or mislocalizing the TRAPP core.
- description: Biochemically separate human TRAPPII and TRAPPIII pools
    containing TRAPPC5 and test whether any discrete TRAPPI-like pool exists in
    vivo.
  experiment_type: complex purification and native fractionation
  hypothesis: TRAPPC5 is present in human TRAPPII/TRAPPIII assemblies, while a
    discrete mammalian TRAPPI complex is absent or not stable in vivo.