## LTN1
- **UniProt:** O94822 · **batch:** proteostasis-batch-2026-06-07c · **review status:** COMPLETE
- **PN placement:** THREE rows. Row 1 (TR) `Translation|Cytosolic translation|Ribosome-associated QC|Ubiquitination` (type=mapped→GO:0016567 protein ubiquitination [already_in_goa_exact]; group→GO:0006515 protein quality control [new_to_goa]). Rows 2 & 3 (UPS) `E3 ubiquitin and UBL ligases|RING ...` and `Ubiquitin and UBL binding|E3 ligase|RING/with UBD|RWD (LTN1)` (group→GO:0061630 ubiquitin protein ligase activity [already_in_goa_exact]; subtype/type=no_mapping; class=context_only).
- **Consistency:** Fully consistent. Deep research, review, and PN all describe LTN1/Listerin as the RING E3 ligase of the RQC complex (LTN1+NEMF+TCF25 on 60S) that poly-ubiquitinates 60S-housed stalled nascent chains for VCP/p97 + proteasomal degradation. Review is comprehensive: GO:0061630 ligase activity (IDA), GO:1990116 RQC catabolic process, GO:1990112 RQC complex, GO:0072344 rescue, GO:0043023 60S binding, GO:0008270 zinc (RING). All PN mappings land on terms LTN1 already holds.
- **PN story / NEW pressure:** No NEW pressure. Every PN-projected term is already in GOA / the review: GO:0016567 protein ubiquitination (already_in_goa_exact), GO:0061630 ligase activity (already_in_goa_exact, ×2 rows), GO:0006515 (broad parent of the specific GO:1990116 LTN1 already holds). Conclusion: **already captured**, and more specifically (LTN1 carries the RQC-specific GO:1990116 / GO:1990112 that the generic PN GO:0006515 / GO:0016567 only approximate).
- **Mapping strategy:** Correctly distinguishes broad from specific per the RQC-branch guidance: group GO:0006515 is the broad parent, and LTN1's own GO:1990116 (ribosome-associated ubiquitin-dependent catabolism) is the specific RQC term — so GO:0006515 should be entailed/context-only, not separately propagated. LTN1 = the RQC E3 ligase, exactly as the branch note states. No node change warranted by this gene.
- **Evidence alignment:** PN row 2 lists "19489725 / rev" as a reference; the review does NOT cite PMID:19489725. The review's definitive structural anchor is PMID:25578875 (RQC complex structure/assembly; LTN1 ligase + NEMF dependence) plus PMID:35452614 (RQC review) and PMID:28757607 (Hel2/40S context, LOW relevance). Minor divergence: the PN row-2 citation (19489725, the original Listerin/neurodegeneration paper) is not in the review's reference set.
- **Verdict:** Fully consistent; PN story already captured (review more specific) — no NEW pressure. **Recommended edits:** none required for terms; treat group-node GO:0006515 as context-only/entailed (LTN1 has the specific GO:1990116) [MAP]; optionally add PMID:19489725 (PN row-2 reference) to `references` if it supports the Listerin RQC/neurodegeneration role [REF].