CLGN PN Consistency Notes
- Generated: 2026-06-18
- Project: PROTEOSTASIS
- Scope: PN consistency rereview against local AIGR review and available deep-research artifacts
- UniProt: O14967
- 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: Calmegin (CLGN) is a testis-specific, type I single-pass integral membrane lectin-type molecular chaperone of the endoplasmic reticulum that is homologous to calnexin and belongs to the calreticulin/calnexin family. Its luminal domain contains a globular concanavalin A-like lectin fold and the extended proline-rich P domain characteristic of calnexin/calreticulin, and it binds calcium ions. Expressed during spermatogenesis in male germ cells, calmegin binds nascent polypeptides and assists the folding and assembly of a range of client proteins required for sperm function, most notably the ADAM-family sperm surface proteins fertilin (ADAM1/ADAM2) and ADAM3, whose maturation and heterodimerization depend on it. It forms a germ-cell ER chaperone complex with the testis-specific protein disulfide isomerase-like protein PDILT and also interacts with the peptidyl-prolyl isomerase cyclophilin B (PPIB), paralleling the calnexin/ERp57 system. Through chaperoning these clients, calmegin is essential for sperm adhesion to and penetration of the egg zona pellucida and for sperm migration from the uterus into the oviduct; loss of function causes male infertility in mice.
- Existing/core annotation action counts: ACCEPT: 7; KEEP_AS_NON_CORE: 3; MARK_AS_OVER_ANNOTATED: 2
PN Consistency Summary
- Consistency: Mostly consistent on identity (testis-specific calnexin-family lectin-type ER membrane chaperone; clients = ADAM1/2/ADAM3; essential for sperm-zona binding/fertility) across notes, YAML, and PN. The friction is the projected GO term: the PN node projects GO:0006487 (the biosynthetic process that adds N-glycans), but CLGN is a lectin chaperone that binds monoglucosylated N-glycans on clients — it does not catalyze glycan transfer. The review correctly annotates GO:0044183 protein folding chaperone / GO:0006457 protein folding, not glycosylation.
- PN story / NEW pressure: PN's "N-glycosylation system" framing over-reaches when projected as GO:0006487 for a lectin chaperone. CLGN's real, review-captured roles (folding chaperone, single fertilization GO:0007338) are already in GOA/review. GO:0006487 is verified real but is the WRONG process for this gene's mechanism → over-reaches; do not ADD to the gene.
- Evidence alignment: PN listed no reference titles for this row. Review anchors on PMID:9177349 (knockout/zona-adhesion), PMID:17507649 (PDILT complex), PMID:9434179 (cloning). No conflict; the divergence is term choice, not evidence.
- Verdict: Identity consistent, but PN GO:0006487 projection over-reaches for a lectin chaperone (binds, not synthesizes, N-glycans); should not propagate to CLGN.
Full Consistency Review
- UniProt: O14967 · batch: proteostasis-batch-2026-06-07 · review status: COMPLETE
- PN placement:
ER proteostasis|Glycoproteostasis|N-glycosylation system|Lectin chaperone ; PN-node mapping: leaf [type] Lectin chaperone no_mapping; [group] N-glycosylation system → mapped GO:0006487 protein N-linked glycosylation (new_to_goa); class/branch unmapped.
- Consistency: Mostly consistent on identity (testis-specific calnexin-family lectin-type ER membrane chaperone; clients = ADAM1/2/ADAM3; essential for sperm-zona binding/fertility) across notes, YAML, and PN. The friction is the projected GO term: the PN node projects GO:0006487 (the biosynthetic process that adds N-glycans), but CLGN is a lectin chaperone that binds monoglucosylated N-glycans on clients — it does not catalyze glycan transfer. The review correctly annotates GO:0044183 protein folding chaperone / GO:0006457 protein folding, not glycosylation.
- PN story / NEW pressure: PN's "N-glycosylation system" framing over-reaches when projected as GO:0006487 for a lectin chaperone. CLGN's real, review-captured roles (folding chaperone, single fertilization GO:0007338) are already in GOA/review. GO:0006487 is verified real but is the WRONG process for this gene's mechanism → over-reaches; do not ADD to the gene.
- Mapping strategy: The
[group] projection is the problem. GO:0006487 is broader/orthogonal to what lectin chaperones do; it is analogous to the TOMM20/HSPA8/RAB7A "broader, rejected" precedent — the node groups the N-glycosylation machinery but its members (OST subunits vs lectin chaperones) do not share GO:0006487. Recommend the group either map to a glycoprotein-QC/folding term (e.g. a chaperone-mediated folding concept) or leave lectin-chaperone members unmapped at this node, so GO:0006487 is not propagated to CLGN.
- Evidence alignment: PN listed no reference titles for this row. Review anchors on PMID:9177349 (knockout/zona-adhesion), PMID:17507649 (PDILT complex), PMID:9434179 (cloning). No conflict; the divergence is term choice, not evidence.
- Verdict: Identity consistent, but PN GO:0006487 projection over-reaches for a lectin chaperone (binds, not synthesizes, N-glycans); should not propagate to CLGN.
Recommended edits: [MAP] Do not propagate GO:0006487 from N-glycosylation system to lectin-chaperone members (CLGN); remap the group to a folding/glycoprotein-QC term or leave lectin chaperones unmapped. [YAML] No glycosylation annotation should be added to CLGN.
PN Dossier Context
- review_batch: proteostasis-batch-2026-06-07
- review_yaml: genes/human/CLGN/CLGN-ai-review.yaml
- PN workbook rows: 1
PN row 1: ER proteostasis | Glycoproteostasis | N-glycosylation system | Lectin chaperone
- UniProt: O14967
- In branches: ER
- PN-node mapping records (path + ancestors):
- [type] ER proteostasis|Glycoproteostasis|N-glycosylation system|Lectin chaperone
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.
- [group] ER proteostasis|Glycoproteostasis|N-glycosylation system
status=mapped scope=ok_for_propagation_to_go GO=[GO:0006487 protein N-linked glycosylation]
rationale: This PN group captures the ER N-glycosylation machinery that installs and processes N-linked glycans during proteostasis. GO protein N-linked glycosylation is the best current propagation target in the local cache.
- [class] ER proteostasis|Glycoproteostasis
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:0006487 protein N-linked glycosylation | scope=ok_for_propagation_to_go | goa_status=new_to_goa | from=ER proteostasis|Glycoproteostasis|N-glycosylation system
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.