## CHIC2
- **UniProt:** Q9UKJ5 · **batch:** proteostasis-batch-2026-06-07 · **review status:** COMPLETE
- **PN placement:** `UPS|E3 ubiquitin and UBL ligases|idiosyncratic UBOX complex|STUB1/CHIC2 complex|noncatalytic` ; **PN-node mapping:** group (idiosyncratic UBOX complex)→GO:0000151 ubiquitin ligase complex (new_to_goa). Subtype/type/branch = no_mapping; class context_only.
- **Consistency:** PARTIAL CONFLICT. The review (and notes) state CHIC2's molecular function is undefined and frame it purely as a palmitoylated membrane/vesicle protein; it makes NO mention of STUB1 or an E3-ligase-complex role. The PN annotation rests on PMID:40796662, which is NOT cited in the review. Per PubMed, PMID:40796662 (Nat Immunol 2025, [DOI](https://doi.org/10.1038/s41590-025-02231-6)) establishes a real STUB1-CHIC2 complex in which CHIC2 is the non-catalytic **adapter** for the E3 ligase STUB1 regulating cytokine-receptor levels in CD8 T cells. So the PN is built on a genuine 2025 finding the review predates/misses.
- **PN story / NEW pressure:** PN asserts a role (member of an E3 ligase complex via STUB1) absent from existing GO and from the review. GO:0000151 "ubiquitin ligase complex" verified real (OLS) and confirmed new_to_goa (CHIC2-goa.tsv has only localization + bare protein-binding). This is a defensible **ADD** as part_of GO:0000151, supported by PMID:40796662. CHIC2 is non-catalytic, so the group-level complex-membership mapping (rather than ligase activity) is the correct, conservative target.
- **Mapping strategy:** Mapping is sound and well-judged: assigns complex membership (GO:0000151) not catalytic activity to a non-catalytic adapter; holds the E3 class context_only to avoid over-propagation. No change needed to the node.
- **Evidence alignment:** No overlap. PN cites PMID:40796662 (the defining STUB1-CHIC2 paper); the review cites only HT-interactome PMIDs (16189514, 19060904, 25416956, 30886144, 32296183, all MARK_AS_OVER_ANNOTATED) plus PMID:11257495 (palmitoylation). The PN reference is the more functionally informative one and is missing from the review.
- **Verdict:** UNDER-CAPTURED by review — PN ADD is justified. **Recommended edits:** [YAML] add PMID:40796662 to references and add a NEW/proposed annotation GO:0000151 (part_of, "STUB1-CHIC2 complex") and an adapter/molecular-function note; [REF] flag that the review's "function undefined" framing is now superseded by the STUB1-CHIC2 adapter finding.