## MAN1B1
- **UniProt:** Q9UKM7 (ER alpha-1,2-mannosidase I / ERManI) · **batch:** proteostasis-batch-2026-06-11 · **review status:** COMPLETE, very thorough (60+ annotations reviewed; rich notes + Falcon).
- **PN placement:** `ER proteostasis|Glycoproteostasis|N-glycosylation system|N-glycan processing|Mannose trimming` ; **PN-node mapping:** subtype mapped→GO:1904382 (mannose trimming in glycoprotein ERAD, ok_for_propagation, more_specific_than_existing_goa); group "N-glycosylation system" mapped→GO:0006487 (protein N-linked glycosylation, entailed_by_goa_closure); type/class/branch no_mapping.
- **Consistency:** Deep research ↔ review ↔ PN annotation are fully consistent. MAN1B1 is correctly framed as a *catalytic* GH47 alpha-1,2-mannosidase (EC 3.2.1.113), not a lectin — matching the PN "Mannose trimming" subtype. The PN subtype→GO:1904382 is well aligned with the review's accepted GO:1904380 (ER mannose trimming) + GO:0036503 (ERAD).
- **PN story / NEW pressure:** No NEW pressure for the catalytic role — already richly captured. One genuinely under-annotated function surfaced by Falcon and incorporated into the review (PMID:32958677): a catalysis-independent, cytoplasmic-tail-dependent ERAD function of misfolded alpha1-antitrypsin, glycan-independent. This is not represented by any existing GO term and is the only defensible NEW direction, but it is single-paper and the review correctly left it as a finding rather than a new term. Conclude: catalytic role already captured; tail-dependent role = future candidate, not yet actionable.
- **Mapping strategy:** Subtype→GO:1904382 is sound (correctly narrower/specific). **Group→GO:0006487 (protein N-linked glycosylation) is mis-entailed for MAN1B1.** Verified via OLS: MAN1B1's GO:0140277 (ER N-glycan trimming) ancestors run through GO:0006491 "N-glycan processing" → glycoprotein *biosynthetic* process — GO:0006487 (the glycan *attachment* step) is a sibling, NOT an ancestor. So the `entailed_by_goa_closure` flag is wrong; MAN1B1 processes/trims N-glycans, it does not install them.
- **Evidence alignment:** PN dossier carries no reference titles (mapping-only); review evidence is extensive and PubMed-verified (PMID:10409699, 10521544, 18003979, 21062743, 22160784, 25411339, 15713668). No divergence.
- **Verdict:** Review excellent and PN-consistent; subtype mapping correct. Flag the group-level GO:0006487 projection as a closure error (catalytic trimmer ≠ N-glycosylation installer).
**Recommended edits:** [MAP] Correct MAN1B1's group projection of GO:0006487 — mark goa_status as NOT entailed_by_goa_closure (GO:0140277/GO:1904380 do not subsume GO:0006487); MAN1B1 is an N-glycan-processing enzyme, not an N-linked-glycosylation (attachment) enzyme.