## HSPB8
- **UniProt:** Q9UJY1 · **batch:** proteostasis-batch-2026-06-07b · **review status:** COMPLETE
- **PN placement:** three rows — `Cytonuclear proteostasis|...|small HSP` (type), `Mitochondrial proteostasis|Chaperone|small HSP` (group), and `Autophagy-Lysosome Pathway|...|Chaperone assisted selective autophagy|CASA complex component` (subtype) ; **PN-node mapping:** sHSP nodes → mapped/ok GO:0044183 protein folding chaperone (new_to_goa); CASA subtype → mapped/ok GO:0035973 aggrephagy (supported_by_goa_regulation).
- **Consistency:** Best-evidenced of the six and fully consistent across notes ↔ review ↔ PN CASA row. HSPB8/HSP22 is an ATP-independent holdase (PMID:14985082) and the sHSP of the CASA complex with BAG3/HSPA8/STUB1 driving aggrephagy of polyQ/filamin (PMID:18006506, 20060297). The PN CASA row even cites matching CASA papers. Mitochondrial row is unsupported (HSPB8 documented in cytoplasm/nucleus, not mitochondria).
- **PN story / NEW pressure:** The CASA/aggrephagy story is ALREADY captured: review has GO:1905337 positive regulation of aggrephagy (IMP) and GO:0034620 cellular response to unfolded protein; GOA carries GO:1905337. PN's GO:0035973 aggrephagy is the parent process and is correctly flagged supported_by_goa_regulation — already captured. The sHSP GO:0044183 projection is the same foldase-vs-holdase over-reach as the other sHSPs (HSPB8 is a holdase per PMID:14985082; GOA has no folding-chaperone MF, core MF is GO:0051082 unfolded protein binding + GO:0051087 protein-folding chaperone binding for the BAG3 interaction).
- **Mapping strategy:** CASA subtype → GO:0035973 needs no change (already covered by stronger GO:1905337 in review/GOA). The sHSP GO:0044183 target is the wrong MF (foldase) for this holdase; prefer GO:0140309 holdase / GO:0051082. Drop the mitochondrial-row chaperone projection.
- **Evidence alignment:** Strong overlap — PN CASA-row titles (CASA complex dynamics; HspB8 promotes autophagic removal in ALS; HSPB8-BAG3-HSP70 stress-granule surveillance) align with the review's CASA PMIDs (18006506, 20060297). No divergence on the autophagy story.
- **Verdict:** CASA/aggrephagy projection sound and already captured; sHSP foldase MF over-reaches, mito row unsupported. **Recommended edits:** [MAP] retarget sHSP GO:0044183 → GO:0140309 / GO:0051082 on Q9UJY1; [MAP] do not project a mitochondrial chaperone term onto HSPB8 (no mito localization). CASA row needs no change.