SSA4 review notes
2026-08-22 re-review
- Identity was rechecked as Saccharomyces cerevisiae SSA4/YER103W, UniProt
P22202: the stress-inducible cytosolic Ssa-family Hsp70 paralog. The
project/workflow citation sentence was removed from the standalone YAML
description; the Falcon report remains an explicit reference in the review.
- The core function remains one ATP-dependent protein folding chaperone
activity (GO:0140662) in cytosolic folding/refolding. The broader GO:0044183
IBA and both GO:0051082 annotations are modified to GO:0140662, while generic
nucleotide binding is marked over-annotated because ATP binding and ATP
hydrolysis are already represented. SSA-family Hsp70 is experimentally
required for folding newly translated cytosolic proteins. PMID:9789005
- The two GO:0006616 annotations retain their existing modification to
GO:0031204. The IMP rationale is narrowed to the strong rapid effect on
post-translational ER prepro-alpha-factor import; the paper's separate
mitochondrial precursor phenotype is recorded but is not encoded by that
ER-scoped replacement. PMID:8754838
- Nuclear localization remains non-core rather than removed because it is an
experimentally observed, reversible starvation response. PMID:11279056
- The plasma-membrane IBA is removed as a stale PAINT transfer. The pinned 2025
GOA row points to PTN002500132, but the current local PTHR19375 PAINT snapshot
carries nucleus and cytosol at that node and no longer carries GO:0005886.
This is a current-node comparison, not an inference from donor count or the
composition of WITH/FROM. A targeted OpenScientist run challenged the prior
KEEP_AS_NON_CORE decision and independently preferred REMOVE because it found
no SSA4-specific plasma-membrane evidence; the yeast plasma-membrane
proteomics annotations it identified concern Ssa1/Ssa2/Ssb1, not Ssa4. Its
live QuickGO absence is consistent with current PAINT, but the report wrongly
implies that the pinned SSA4 snapshot lacks the 2025 IBA and speculates about
donor origins. Those claims remain marked DISPUTED and are not used.
[file:yeast/SSA4/SSA4-hypotheses/existing-go-0005886-keep-as-non-core/openscientist.md
"The only yeast PM evidence for this family ... covers the paralogs
Ssa1/Ssa2/Ssb1 ... and excludes Ssa4"]
- The UNFOLDED_PROTEIN_BINDING project row now uses GO:0140662 for SSA4, aligning
the project decision with the review's ATP-dependent Hsp70 mechanism. All nine
generic protein-binding IPI rows are now represented separately and modified
to Hsp70 or heat-shock-protein binding according to the GOA partner; the three
protein-folding and three unfolded-client IGI rows are likewise retained as
distinct SSA1/SSA2/SSA3-linked records. No module currently names SSA4.
2026-08-27 reviewer follow-up
- The imported SGD/Alliance description was not accepted wholesale: its
SRP-dependent cotranslational clause conflicts with the primary SSA/Ydj1
translocation evidence and the review's GO:0031204 replacement. The description
rubric now explicitly scores and explains that mechanistic error.
- A newly cached primary study directly supports a second conditional nuclear
localization context. Under cadmium stress, ScSsa4 translocates to the nucleus,
associates with Pom34, and regulates VHS1 expression in a pathway that reduces
cadmium accumulation. PMID:39456809 Both nucleus rows remain KEEP_AS_NON_CORE because starvation and cadmium
trigger context-specific relocalization rather than defining Ssa4's default
cytosolic site.
- The redundant synthetic NEW GO:0140662 row was removed. GO:0140662 remains the
replacement for each broader chaperone/client-binding row and the molecular
function in core_functions; the review therefore contains exactly one record per
one of the 33 pinned GOA rows. Generic nucleotide binding is now MODIFY to the
existing specific ATP-binding term GO:0005524.
- The four remaining interactome references now carry manual caveats. Their GOA
partner identities are retained, but genome-scale co-complex, prediction, paralog-
heteromer, and affinity-enrichment datasets are not described as targeted proof of
direct binary contact when the specific edge is absent from the narrative text.
2026-09-29 IBA follow-up
- Rechecked all eight GO_REF:0000033 IBA rows against
interpro/panther/PTHR19375/PTHR19375-paint.tsv. The accepted nucleus,
cytoplasm, cytosol, ATPase, heat-shock-protein-binding, protein-folding
chaperone, and protein-refolding transfers all still trace to current PAINT
rows; the pinned plasma-membrane IBA remains stale because current
PTN002500132 carries only GO:0005634 nucleus and GO:0005829 cytosol.
- Recorded the 2026 fungal PTN001065099
GO:0042026 protein refolding NOT/IRD
and retained the SSA4 transfer because SSB2/SSZ1 tracing places PTN001065099
on the ribosome-associated Ssb/Ssz loss branch, whereas the retained
PTN000452648 refolding IBD is seeded by cytosolic Ssa-family SSA1.
- Added missing
propagation_review.source_entities blocks for the accepted
IBA rows and expanded the PTN-only chaperone IBA with representative current
donors from PTN000452648.
- Searched PubMed for exact
SSA4/Ssa4/YER103W mentions in 2025-2026 and
found no new exact-match papers that change the Ssa4 curation.
2026-10-01 current-GOA refresh follow-up
- Forced a current
fetch-gene refresh because live GOA for SSA4 has moved from
33 historical rows to 20 rows. The review now keeps all historical source
assertions and marks the 15 rows that no longer exactly match live GOA as
retired: true.
- Reviewed the two newly seeded exact live rows: InterPro2GO now contributes
GO:0005524 ATP binding through Hsp70 domain IPR013126, and SGD now curates
direct GO:0140662 ATP-dependent protein folding chaperone from the abstract-only
Ydj1/Ssa-isoform study in PMID:32299842.
- Rechecked exact live-row bookkeeping after the refresh. All 20 current GOA
signatures are represented by unretired YAML rows, including the 2026 PAINT
donor sets for GO:0005737 cytoplasm, GO:0016887 ATP hydrolysis activity,
and GO:0044183 protein folding chaperone.
- Corrected the active PMID:37968396 generic protein-binding row after the live
IntAct set retained the Sis1 edge but not the old Ssa2/Sse1 edges. The row now
names Sis1 and proposes GO:0031072 heat shock protein binding, matching the
other live Sis1 row.
- Searched PubMed for exact
SSA4/Ssa4/YER103W mentions in 2025-2026 and
found no new exact-match papers that change the Ssa4 curation.