## FBXL18
- **UniProt:** Q96ME1 · **batch:** proteostasis-batch-2026-06-13 · **review status:** COMPLETE
- **PN placement:** `UPS|E3 ubiquitin and UBL ligases|Cul1 substrate receptor|F-box|LRR` ; **PN-node mapping:** group-level `mapped / ok_for_propagation_to_go / GO:1990756`; F-box+LRR subtype/type `no_mapping`; class `context_only / too_broad / GO:0061630`; branch `no_mapping`. NB only IPR032675 auxiliary domain listed (no IPR001611), but IPR001810 F-box signature present.
- **Consistency:** Strong. Falcon, review YAML, and PN mapping agree FBXL18 is the SCF(FBXL18) substrate receptor. Cache-verified core: K48-degradation of fellow F-box protein FBXL7 (FQ motif, Lys109; limits apoptosis — PMID:25654763, full text). Falcon adds K48 degradation of XPB/ERCC3 (reconstituted SCF^FBXL18) and a **non-degradative K63 mode** on AKT and PTEN (activating PI3K/AKT) — flagged UNVERIFIED (DOI-only leads, PTEN is a 2024 preprint). Dual-mode framing is internally consistent.
- **PN story / NEW pressure:** PN asserts generic adaptor MF (GO:1990756, verified real); GOA carries NO MF term at all (only BP/CC). Review uses GO:1990756 in core_functions (no MF to MODIFY). Correct. The K63 non-degradative mode is genuine NEW pressure not captured by GO:0031146/catabolic terms; the review handles it via a second core_function (MF still GO:1990756; BP GO:0051897 positive regulation of PI3K/AKT, verified real) rather than proposing an unverified MF — conservative and acceptable. No defensible additional real NEW GO term identified.
- **Mapping strategy:** Gene does not change the node. FBXL7 (and XPB) are validated K48 substrates → degradative adaptor MF grounded, not orphan. The K63 mode rests on unverified leads; group GO:1990756 still applies (substrate adaptor regardless of chain type). Catalysis correctly excluded from sub-nodes (RBX1 RING). Canonical SCF (reconstituted with CUL1/SKP1/RBX1) — no non-canonical flag.
- **Evidence alignment:** PN reference only "15340381/rev" (placeholder); review does not cite it. Review uses PMID:25654763 (verified) + 33234069 (family) + falcon. Benign divergence; K63-mode primary papers not PubMed-verified in cache.
- **Verdict:** CONSISTENT / ACCEPT mapping. No edits required; adaptor-MF pattern correctly applied; degradative substrate (FBXL7) validated; K63 non-degradative mode noted but appropriately not over-asserted.