## FKBPL
- **UniProt:** Q9UIM3 · **batch:** proteostasis-batch-2026-06-07b · **review status:** COMPLETE
- **PN placement:** `Cytonuclear proteostasis|Chaperone|HSP90 system|HSP90 cochaperone|CC-TPR and PPIase domain containing`. **PN-node mapping:** type `HSP90 cochaperone`=mapped→**GO:0051879 Hsp90 protein binding** (more_specific_than_existing_goa); subtype `CC-TPR and PPIase domain containing`=no_mapping (correctly declines a subtype-level PPIase mapping because members are mixed/non-canonical); group/class/branch=no_mapping.
- **Consistency:** Notes, review YAML, and PN mapping are fully consistent. All three correctly frame FKBPL/WISp39 as a **non-canonical, catalytically inactive FKBP** (no functional PPIase domain) that acts as a TPR/HSP90 co-chaperone forming a ternary HSP90AB1–p21(CDKN1A) complex regulating p21 stability, plus a secreted anti-angiogenic pool. No contradiction.
- **PN story / NEW pressure:** GO:0051879 (OLS-verified) is **not** in FKBPL's GOA (GOA MF rows are all bare protein binding to ANKRD49/CALCOCO2 HT-interactome hits — HSP90 is not among the IPI WITH partners), confirming PN's more_specific_than_existing_goa. The review **adds** GO:0051879 as the single core molecular function (supported by UniProt FUNCTION/SUBUNIT). This matches the PN projection exactly. Conclusion: legitimate ADD, executed in the review. No over-reach: PN correctly does NOT project PPIase activity (which would be wrong for this degenerate FKBP).
- **Mapping strategy:** Cleanly handled. The subtype no_mapping is the key correct decision — it prevents propagating PPIase activity (GO:0003755) to a non-catalytic member, the same restraint the FKBP8 dossier applies in reverse. Gene-level review and PN projection agree on the one defensible shared MF (HSP90 binding). No mapping change needed.
- **Evidence alignment:** PN dossier lists no reference titles for FKBPL; alignment is by biology (HSP90 co-chaperone). Review evidence is reviewer-supplied (PMID:10521921 radioresistance/NAS; PMID:25767277 anti-angiogenic/extracellular; PMID:15664193 cited in notes for the WISp39–p21–HSP90 mechanism; recurrent ANKRD49/CALCOCO2 HT hits). The core HSP90/p21 mechanism rests on UniProt + PMID:15664193 rather than a GOA-anchored row.
- **Verdict:** Consistent; PN GO:0051879 projection validated and added as the core MF; subtype-level PPIase correctly withheld. **Recommended edits:** none required; [REF] optionally add PMID:15664193 (Jascur et al., WISp39/HSP90/p21) as an explicit reference entry in the review YAML to anchor the GO:0051879 core function (currently it is only in notes, with the YAML core_function relying on UniProt text).