## CAND1
- **UniProt:** Q86VP6 · **batch:** proteostasis-batch-2026-06-06 · **review status:** COMPLETE
- **PN placement:** `Ubiquitin Proteasome System|E3 ubiquitin and UBL ligases|CRL regulator|F-box exchange factor|Armadillo-like` ; **PN-node mapping:** F-box-exchange-factor type/subtype → mapped/ok_for_propagation GO:1990757 ubiquitin ligase activator activity (new_to_goa); CRL-regulator group → context_only/too_broad GO:1904666; E3-ligases class → context_only GO:0061630.
- **Consistency:** Consistent. PN, review, notes and (no separate deep-research file; review references serve) all describe CAND1 as the CUL1-RBX1-binding **F-box/substrate-receptor exchange factor** that remodels SCF/CRL complexes and is a positive regulator of CRL activity in vivo (PMID:12504026, 15537541, 21249194). PN's "F-box exchange factor / Armadillo-like (HEAT-repeat)" matches the review's mechanism exactly.
- **PN story / NEW pressure:** PN projects GO:1990757 "ubiquitin ligase activator activity" (verified real; def "binds to and increases the activity of a ubiquitin ligase"). This aligns with the review's conclusion that CAND1 is an in-vivo positive regulator of CRL activity and is genuinely NEW to GOA (current GOA carries SCF assembly / part-of CRL, not an activator MF). It is defensible as ADD. Separately, the review independently proposes a finer NEW term "cullin-RING ligase substrate-receptor exchange factor activity" — I verified via OLS that NO such GO term exists (candidate, correctly flagged as new). So GO:1990757 is the best existing real term and is a sound PN-node addition; the review's bespoke term is a legitimate future request.
- **Mapping strategy:** Type/subtype projection of GO:1990757 onto CAND1 is appropriate and adds value over current GOA. The group/class context_only (too_broad) calls are correct (CRL-regulator descendants mix inhibitors and activators; E3 class mixes catalytic/scaffold/adaptor). No precedent-style over-broadening here.
- **Evidence alignment:** PN row cites reference 23453757 (title not resolved in dossier). Review supports activator/exchange role via PMID:12504026, 15537541, 21249194, 12609982. Overlap is thematic (CRL assembly regulation); the PN-cited 23453757 is not in the review's reference list — minor divergence worth noting.
- **Verdict:** Consistent and the strongest ADD case of the six — GO:1990757 (real) is a defensible new MF for CAND1, matching both PN and the review's positive-regulator framing. **Recommended edits:** [YAML] consider adding GO:1990757 ubiquitin ligase activator activity to CAND1 existing/core (currently only proposed as a bespoke new term); [REF] confirm PN reference 23453757 and add to the review if it supports the activator role.