cryabb (alpha-crystallin B chain b) — curation notes
Zebrafish cryabb (cryab2, hspb5b, alphaB2-crystallin; UniProt A0A8M9Q8E3) is the broadly
expressed alphaB-crystallin paralog. Primary source: Smith et al. 2006 PMID:16420472. The 2026-09-27 session migrated the review off obsolete GO:0051082
(issue #2222) and proposed a holdase chaperone activity NTR.
Re-review 2026-09-29
Validation before edits: 1 error (5 yaml rows no longer in GOA) and 3 PENDING rows.
What changed and why:
- Removed the five rows absent from the refreshed GOA: GO:0051082 IBA and IDA (obsolete;
the IDA was migrated by ZFIN to GO:0140309), GO:0005212 IEA via GO_REF:0000120,
GO:0009892 IEA, GO:0046872 IEA.
- GO:0140309 unfolded protein holdase activity (IDA, new row): MODIFY -> holdase chaperone
activity NTR. The assay is the classic holdase readout PMID:16420472, but the
term definition (checked via QuickGO) is still a carrier activity that "escorts it to an
acceptor molecule or to a specific location", which was not tested (go-ontology#30552).
Same replacement as the GO:0042026 protein refolding IBA row, so actions are consistent.
- GO:0005886 plasma membrane (IEA, ARBA, new row): REMOVE. No signal/TM features, no UniProt
SUBCELLULAR LOCATION line, ZFIN ND for CC; cryabb is a soluble lens protein PMID:16420472.
- GO:0005212 structural constituent of eye lens (IEA, InterPro, new row): KEEP_AS_NON_CORE;
GO:0005198 structural molecule activity (IEA, ARBA): ACCEPT -> MARK_AS_OVER_ANNOTATED
(generic parent, minor lens component, activity is chaperoning).
- ZFIN morphant IMP rows (PMID:25866181, abstract-only, cryabb not named in the abstract;
curator deferred to): GO:0007519 skeletal muscle tissue development ACCEPT ->
KEEP_AS_NON_CORE and GO:0060047 heart contraction ACCEPT -> KEEP_AS_NON_CORE (downstream
tissue/organ phenotypes); GO:0030239 myofibril assembly kept ACCEPT as the process where
the holdase does the work PMID:25866181. core_functions.directly_involved_in trimmed accordingly.
- Added two cached papers: Elicker & Hutson 2007 PMID:17888590 (cryabb = hspb5b is not in that list,
so zebrafish heat induction is modest) and Park et al. 2023 [PMID:37577747 "Our data
suggest that cryabb functions as a stress–response gene regulated by both glucocorticoid
stress and oxidative stress."; "the loss of αB-crystallin function is associated with a
cardiac phenotype that presents as embryonic cardiac edema"]. Used for GO:0009408 (ACCEPT,
argued from the sHSP node placement), GO:0060047 and GO:0036438.
- Rewrote all templated summaries/reasons, replaced deep-research-only support with primary
quotes where available, added reference_review to every PMID, rewrote description
(removed UniProt keyword commentary), added suggested_questions/experiments.
Validation after edits: zero errors, zero warnings. Open point: no zebrafish localization
experiment exists (ZFIN ND), and the muscle evidence is morpholino-only.