## UBAC2
- **UniProt:** Q8NBM4 · **batch:** proteostasis-batch-2026-06-11 · **review status:** COMPLETE (thorough; rhomboid PSEUDOprotease, ERAD scaffold + FAF2 ER receptor + ER-phagy receptor + Wnt)
- **PN placement:** 2 rows — `UPS|E3 ubiquitin and UBL ligases|idiosyncratic RING complex|LMBR1L-GP78-UBAC2 complex|noncatalytic / UBA, transmembrane`; `UPS|Ubiquitin and UBL binding|trafficking|ERphagy|UBA`. **PN-node mapping:** LMBR1L-GP78-UBAC2 subtype/type no_mapping (noncatalytic, covered by parent); idiosyncratic-RING-complex group→GO:0000151 ubiquitin ligase complex (new_to_goa); E3-ligase class context_only GO:0061630 (too_broad); ERphagy/UBA-binding rows all no_mapping/context_only (GO:0140036 too_broad). Projected: GO:0000151 (new).
- **Consistency:** Excellent. Deep research, review and PN concur that UBAC2 is a **catalytically inactive rhomboid pseudoprotease** (no Ser/His dyad), an ER-membrane scaffold/adaptor — NOT an enzyme. The PN explicitly tags the LMBR1L-GP78-UBAC2 subtype as "noncatalytic / UBA, transmembrane" and assigns the COMPLEX (GO:0000151), not catalytic activity, to the group — exactly matching the review's REMOVE of the IBA serine-type endopeptidase activity (GO:0004252). The PN correctly does NOT project GO:0061630 to UBAC2. No contradictions.
- **PN story / NEW pressure:** PN's only NEW projection is GO:0000151 ubiquitin ligase complex (verified real; NOT in GOA) from the LMBR1L-GP78(AMFR)-UBAC2 idiosyncratic-RING-complex membership (PMID:31073040). UBAC2 is genuinely a non-catalytic subunit of this AMFR/GP78-containing E3 complex, so complex membership is a DEFENSIBLE ADD — and one the review does NOT currently capture (review has the Wnt BP via this complex but no GO:0000151 CC term). Conclude: pseudoprotease/scaffold correctly captured; GO:0000151 a defensible NEW the review missed.
- **Mapping strategy:** Exemplary. Resolves the pseudoprotease trap (no serine endopeptidase MF — matches prior REMOVE precedent), assigns complex membership not catalysis to the non-catalytic subunit, and conservatively leaves the ERphagy/UBA-binding rows unmapped (avoids over-broad GO:0140036 reader propagation). The ER-phagy biology IS captured at the gene level (review GO:0061709 reticulophagy IMP). No node-status change warranted.
- **Evidence alignment:** Partial. PN complex row cites "31073040" (LMBR1L/Wnt paper) — IS in the review (HIGH/VERIFIED, source of the Wnt + LMBR1L annotations). The ERphagy row carries no PN reference title; the review's ER-phagy evidence (PMID:39284914, HIGH) is gene-specific and richer. Good overlap on the one cited PMID; no divergence.
- **Verdict:** Fully consistent; pseudoprotease status and scaffold role correctly handled by BOTH review (REMOVE GO:0004252) and PN (noncatalytic tag, no GO:0061630). GO:0000151 complex membership is a defensible ADD the review omits.
- **Recommended edits:** [YAML] add GO:0000151 ubiquitin ligase complex (part_of; LMBR1L-AMFR/GP78-UBAC2 complex, PMID:31073040) as a non-core CC — currently absent from the review. [MAP] none — node mapping is correct; complex (not catalytic) target for the non-catalytic subunit is the right call.