## P4HA3
- **UniProt:** Q7Z4N8 · **batch:** proteostasis-batch-2026-06-11 · **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=GO:0032964 collagen biosynthetic process (class/branch=no_mapping). Projection goa_status=new_to_goa.
- **Consistency:** Consistent. Review, deep research, PN annotation, and mapping describe the third catalytic alpha-3 subunit of C-P4H (EC 1.14.11.2), [alpha(III)]2-beta2 tetramer with PDI, ER-lumenal; intermediate peptide-binding properties; broadly but weakly expressed. PN placement matches. EXP evidence (PMID:14500733) anchors the catalytic function.
- **PN story / NEW pressure:** PN asserts GO:0032964 as new_to_goa; P4HA3 GOA has no collagen-process BP term (only MF/CC). GO:0032964 verified real via OLS. Unlike P4HA1/P4HA2, this review has proposed_new_terms: [] — it did not flag the BP gap, so the PN projection actually adds a BP role the review omitted. The projection is nonetheless defensible (same catalytic logic as the paralogs) and consistent with the review's BP-free MF annotations. Conclusion: defensible ADD.
- **Mapping strategy:** Correct. Catalytic subunit; group-level GO:0032964 appropriate, narrower than unmapped class. No node change. For paralog-uniformity, the review's empty proposed_new_terms is a minor inconsistency vs P4HA1/P4HA2 (which propose GO:0018401/GO:0032964).
- **Evidence alignment:** PN dossier mapping-only. Review core: EXP PMID:14500733 (founding characterization), reviews PMID:34009234. Numerous cancer-biomarker refs (PMID:36588128, 39362976, 39504328, 39394821) beyond PN scope — expected divergence. Core biochemistry aligns.
- **Verdict:** Consistent; PN GO:0032964 ADD defensible and genuinely new to GOA; minor note that this review omitted the BP-gap proposal its paralogs made.
- **Recommended edits:** [YAML] Consider adding a peptidyl-proline-hydroxylation / collagen-biosynthetic-process entry to P4HA3 proposed_new_terms (GO:0018401 / GO:0032964) for parity with P4HA1/P4HA2 and to match the PN projection.