## CAND2
- **UniProt:** O75155 · **batch:** proteostasis-batch-2026-06-13 · **review status:** COMPLETE
- **PN placement:** `UPS|E3 ubiquitin and UBL ligases|CRL regulator|F-box exchange factor|Armadillo-like` ; **PN-node mapping:** type/subtype mapped, scope=ok_for_propagation_to_go, GO:1990757 ubiquitin ligase activator activity (group/class context_only; branch no_mapping)
- **Consistency:** Deep research (falcon, HIGH), review YAML, and the dossier note all agree on the substance: CAND2/TIP120B is a muscle-enriched, non-catalytic CAND-family CRL/SCF F-box exchange factor (paralog of CAND1, less efficient; Wang 2025 kinetics, Shiraishi 2007 myogenin/CUL1, Liu 2002). All 14 GOA rows are reviewed. One framing mismatch: the PN node projects an *activator* term, but the review (correctly) stresses CAND2 can be functionally inhibitory in muscle (it suppresses SCF-mediated myogenin ubiquitination).
- **PN story / NEW pressure:** The PN core MF (cullin-RBX binding / exchange-factor activity) is genuinely absent from GOA. The review adds GO:0097602 cullin family protein binding as NEW (verified real, ISS basis) — well-justified and the right altitude. No catalytic-ligase term assigned (correct). SCF complex assembly (GO:0010265) already captures the BP.
- **Mapping strategy:** Concern. GO:1990757 ("Binds to and increases the activity of a ubiquitin ligase" — verified, strictly positive) over-reaches: CAND family activity is directionally context-dependent (exchange/remodeling, inhibitory in the muscle/myogenin context), echoing the dossier's own "different directionality" caveat at the group level. The review deliberately does NOT assign GO:1990757. PN-projected term is broader/mis-directional vs the review's GO:0097602 + GO:0010265.
- **Evidence alignment:** Divergent. PN cites only PMID:40011427 (the 2025 CAND2 exchange-factor paper); the review captures this same study via the falcon report (Wang 2025 Nat Commun) but does not list PMID:40011427 in `references`. Review PMIDs (12207886, 12692129, 23864651, 32296183) are not in the PN row.
- **Verdict:** Substantively consistent; PN activator mapping (GO:1990757) over-reaches and conflicts with the review's non-catalytic/context-inhibitory exchange-factor framing. Prefer review's GO:0097602 + GO:0010265. **Recommended edits:** [MAP] downgrade CAND2 type/subtype GO:1990757 mapping toward exchange-factor/cullin-binding (GO:0097602) or context_only, rather than "activator". [REF] add PMID:40011427 to CAND2 review `references` (currently only cited via falcon report).