COLGALT2 PN Consistency Notes
- Generated: 2026-06-18
- Project: PROTEOSTASIS
- Scope: PN consistency rereview against local AIGR review and available deep-research artifacts
- UniProt: Q8IYK4
- AIGR review status: COMPLETE
- Review batch: proteostasis-batch-2026-06-07
- Batch change status: added
Source Files Checked
Deep Research Files
- No
*-deep-research*.md file found in this gene directory.
AIGR Review Snapshot
- Description: COLGALT2 (collagen beta(1-O)galactosyltransferase 2; also known as GLT25D2, glycosyltransferase 25 family member 2) is an endoplasmic reticulum-luminal, manganese-dependent glycosyltransferase that catalyzes the transfer of beta-galactose from UDP-galactose to hydroxylysine residues of collagens, forming galactosyl-O-hydroxylysine (Gal-O-Hyl). This is the first step of collagen O-glycosylation, which precedes glucosylation to generate the glucosylgalactosyl-hydroxylysine (Glc-Gal-O-Hyl) disaccharide found on collagens and other proteins with collagenous domains. It is a member of the glycosyltransferase 25 (GT25) family and a paralog of COLGALT1, with which it shares procollagen galactosyltransferase activity (EC 2.4.1.50) but no glucosyltransferase activity. The mature protein is a soluble ER-luminal enzyme retained in the ER by a C-terminal SRDEL (KDEL-like) retention signal. Compared with the ubiquitously expressed COLGALT1, COLGALT2 has a more restricted tissue distribution, with expression enriched in brain and skeletal muscle.
- Existing/core annotation action counts: ACCEPT: 7; KEEP_AS_NON_CORE: 1; MARK_AS_OVER_ANNOTATED: 4; NEW: 1
PN Consistency Summary
- Consistency: Consistent. Review, PN annotation, and PN-node mapping agree: COLGALT2/GLT25D2 is a soluble ER-luminal, Mn2+-dependent collagen beta(1-O)galactosyltransferase (EC 2.4.1.50), paralog of COLGALT1, brain/skeletal-muscle-enriched. No contradictions.
- PN story / NEW pressure: PN projects GO:0032964 collagen biosynthetic process (verified real OLS). Review captures the more specific GO:0050211 procollagen galactosyltransferase activity (MF) and proposes GO:0180062 protein O-linked glycosylation via galactose as a NEW BP (replacing reliance on the downstream GO:0030199). The PN pathway context is consistent with and broader than these. Conclusion: already captured (review goes finer-grained); no PN-driven NEW pressure.
- Evidence alignment: PN row has no reference titles; review's enzymatic evidence rests mainly on PMID:19075007 and UniProt (plus high-throughput protein-binding PMIDs marked over-annotated). Collagen-biosynthesis evidence base is thinner than COLGALT1's but adequate and concordant with the mapping. No divergence.
- Verdict: Consistent; PN collagen-biosynthesis role already captured (more specifically) in review. No edits required.
Full Consistency Review
- UniProt: Q8IYK4 · batch: proteostasis-batch-2026-06-07 · review status: COMPLETE
- PN placement:
ER proteostasis | Maturation and folding of specific substrates | ER collagen processing and folding ; PN-node mapping: group=mapped, scope=ok_for_propagation_to_go, GO:0032964 collagen biosynthetic process (class/branch = no_mapping)
- Consistency: Consistent. Review, PN annotation, and PN-node mapping agree: COLGALT2/GLT25D2 is a soluble ER-luminal, Mn2+-dependent collagen beta(1-O)galactosyltransferase (EC 2.4.1.50), paralog of COLGALT1, brain/skeletal-muscle-enriched. No contradictions.
- PN story / NEW pressure: PN projects GO:0032964 collagen biosynthetic process (verified real OLS). Review captures the more specific GO:0050211 procollagen galactosyltransferase activity (MF) and proposes GO:0180062 protein O-linked glycosylation via galactose as a NEW BP (replacing reliance on the downstream GO:0030199). The PN pathway context is consistent with and broader than these. Conclusion: already captured (review goes finer-grained); no PN-driven NEW pressure.
- Mapping strategy: No change. Group-node → GO:0032964 is the same defensible shared-pathway mapping as for COLGALT1/CRTAP/P3H1 in this collagen-processing group; appropriate process-level umbrella, ancestors correctly no_mapping. The review's NEW GO:0180062 would be the more precise gene-level BP but does not change the node mapping.
- Evidence alignment: PN row has no reference titles; review's enzymatic evidence rests mainly on PMID:19075007 and UniProt (plus high-throughput protein-binding PMIDs marked over-annotated). Collagen-biosynthesis evidence base is thinner than COLGALT1's but adequate and concordant with the mapping. No divergence.
- Verdict: Consistent; PN collagen-biosynthesis role already captured (more specifically) in review. No edits required.
PN Dossier Context
- review_batch: proteostasis-batch-2026-06-07
- review_yaml: genes/human/COLGALT2/COLGALT2-ai-review.yaml
- PN workbook rows: 1
PN row 1: ER proteostasis | Maturation and folding of specific substrates | ER collagen processing and folding
- UniProt: Q8IYK4
- In branches: ER
- PN-node mapping records (path + ancestors):
- [group] ER proteostasis|Maturation and folding of specific substrates|ER collagen processing and folding
status=mapped scope=ok_for_propagation_to_go GO=[GO:0032964 collagen biosynthetic process]
rationale: This PN group contains ER factors dedicated to collagen maturation, processing, and folding. Collagen biosynthetic process captures the shared substrate-specific pathway context.
- [class] ER proteostasis|Maturation and folding of specific substrates
status=no_mapping scope= GO=[]
rationale: Reviewed as a broad PN category rather than a single GO class. The member genes span multiple activities, complexes, or contexts, so direct propagation from this node would overstate the shared biology.
- [branch] ER proteostasis
status=no_mapping scope= GO=[]
rationale: Reviewed as a top-level PN branch. This is a systems/taxonomy umbrella, not a direct GO assertion; narrower child curations carry any propagating GO mappings.
Projected GO annotations (1)
- GO:0032964 collagen biosynthetic process | scope=ok_for_propagation_to_go | goa_status=new_to_goa | from=ER proteostasis|Maturation and folding of specific substrates|ER collagen processing and folding
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.