| Function/Process | Evidence type (review/primary, assay) | Key findings | Subcellular location/compartment | Key interaction/complex context (TRAPPII/TRAPPIII, Rab1/Rab11) | Citations (pqac IDs) |
|---|---|---|---|---|---|
| Gene/protein identity and complex membership | Primary; tandem-affinity purification/proteomics and interaction mapping | Human C4orf41 is TRAPPC11, a bona fide mammalian TRAPP subunit; recovered with known TRAPP baits and implicated in early secretory trafficking | TRAPP-associated membranes of the early secretory pathway | TRAPP complex component; later literature places it in metazoan TRAPPIII | (pqac-00000001, pqac-00000003, pqac-00000004) |
| Early ER-to-Golgi trafficking | Primary; RNAi depletion, VSV-G transport assay, fluorescence microscopy, BFA perturbation | TRAPPC11 depletion causes cargo arrest before/at ERGIC and Golgi fragmentation; VSV-G fails to efficiently reach/pass through Golgi | ER exit sites, ERGIC, Golgi | TRAPP-mediated early secretory pathway function; TRAPPIII-associated in later models | (pqac-00000001, pqac-00000016, pqac-00000012) |
| Golgi organization/integrity | Primary and review; patient fibroblast imaging, immunoblot | Loss or mutation of TRAPPC11 leads to Golgi dispersal/fragmentation and reduced full-length TRAPPC11 protein | Golgi apparatus | Loss of interaction with TRAPP core, especially TRAPPC2, is reported for disease variants | (pqac-00000002, pqac-00000012, pqac-00000013) |
| Rab GEF pathway assignment | Reviews/structural synthesis; cryo-EM-informed models | In metazoans, TRAPPC11 is assigned to TRAPPIII, the complex that activates Rab1; TRAPPII activates Rab11 | Membrane-associated TRAPP complexes on secretory/autophagy membranes | TRAPPIII-specific subunit; Rab1 pathway, contrasted with TRAPPII/Rab11 | (pqac-00000006, pqac-00000007, pqac-00000009, pqac-00000022) |
| TRAPPIII architecture/assembly | Structural review; cryo-EM/density-map interpretation | TRAPPC11 is metazoan-specific, binds TRAPPC2L, and its C-terminal region meets TRAPPC8 at the outer TRAPPIII architecture vertex with TRAPPC12/13 | TRAPPIII complex scaffold at membrane surface | TRAPPIII assembly with TRAPPC8/12/13; contributes to Rab1-specific complex organization | (pqac-00000004, pqac-00000007, pqac-00000022) |
| Protein glycosylation | Primary and review; patient biopsies/fibroblasts, immunoblot, glycosylation markers | TRAPPC11 deficiency causes protein hypoglycosylation; severe α-dystroglycan hypoglycosylation is seen in affected muscle/brain, with altered N-glycosylation markers in cells | ER/Golgi glycoprotein processing pathway | Function extends beyond generic trafficking; may include TRAPP-independent effects on N-linked glycosylation/LLO homeostasis | (pqac-00000002, pqac-00000012, pqac-00000015, pqac-00000006) |
| Autophagy/autophagosome maturation | Primary and review; LC3-II flux, LC3-LAMP1 colocalization, protease-protection assay | TRAPPC11 acts upstream of autophagosome sealing; deficiency reduces autophagic flux and yields unsealed isolation membranes in some patient cells | Isolation membrane/autophagosome, lysosome-related compartments | TRAPPIII-associated autophagy role; recruits/acts with autophagy machinery downstream of initiation | (pqac-00000011, pqac-00000015, pqac-00000006, pqac-00000012) |
| Lysosomal/autophagic marker changes | Review of primary patient-cell work; LAMP1 localization/levels | Altered LAMP1 localization and reduced LAMP1 levels in patient fibroblasts support lysosomal/autophagic perturbation | Lysosome/autolysosome-related compartments | Downstream consequence of TRAPPC11 dysfunction within TRAPPIII-linked trafficking/autophagy networks | (pqac-00000002, pqac-00000012) |
| Functional importance of C-terminus/domains | Primary; variant analysis in patient cells | Variants affecting the foie gras region or extreme carboxy terminus impair trafficking, glycosylation, and in some cases autophagy, indicating the C-terminus is critical for function | TRAPPIII structural subunit with functionally important C-terminal region | Supports structural role within TRAPPIII rather than enzyme catalysis | (pqac-00000000, pqac-00000011, pqac-00000015) |
| Disease-relevant cellular role | Review and primary human genetics/cell biology | TRAPPC11 variants cause multisystem “TRAPPopathy” with consistent muscle involvement and cellular defects in trafficking, Golgi maintenance, glycosylation, and autophagy | Highest functional readout in muscle, fibroblasts, liver-related pathways | Autosomal-recessive TRAPPC11 deficiency; ClinVar lists >60 pathogenic/likely pathogenic variants | (pqac-00000002, pqac-00000018) |


*Table: This table summarizes the experimentally supported functional annotation of human TRAPPC11 (UniProt Q7Z392), including trafficking, Golgi, glycosylation, and autophagy roles. It also captures the current consensus that TRAPPC11 is a metazoan TRAPPIII subunit linked to Rab1 rather than Rab11 biology.*