Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
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PANTHER phylogenetic-tree annotation propagates conserved Hsp90 chaperone functions (ATP binding, ATP hydrolysis, protein folding, cellular response to heat, protein stabilization, identical protein binding, cytosol localization) to S. cerevisiae HSP82.
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
Electronic Gene Ontology annotations created by ARBA machine learning models
Combined Automated Annotation using Multiple IEA Methods
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Combined automated IEA pipelines annotate HSP82 with ATP binding, ATP hydrolysis activity, protein folding, and unfolded protein binding from UniProt features.
Contribution of N- and C-terminal domains to the function of Hsp90 in Saccharomyces cerevisiae.
Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry.
Subcellular localization of the yeast proteome.
N-terminal residues regulate the catalytic efficiency of the Hsp90 ATPase cycle.
Aha1 binds to the middle domain of Hsp90, contributes to client protein activation, and stimulates the ATPase activity of the molecular chaperone.
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Aha1 binds the middle domain of Hsp90 (HSP82), stimulates ATPase activity, and contributes to client protein activation, anchoring HSP82 in the canonical Hsp90 co-chaperone cycle.
The molecular chaperone Hsp90 plays a role in the assembly and maintenance of the 26S proteasome.
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HSP82/Hsp90 is required for assembly and maintenance of the 26S proteasome in vivo, supporting GO:0043248 proteasome assembly as a client-dependent secondary function.
"Functional loss of Hsp90 using a temperature-sensitive mutant in yeast caused dissociation of the 26S proteasome."
Global analysis of protein localization in budding yeast.
The ctf13-30/CTF13 genomic haploinsufficiency modifier screen identifies the yeast chromatin remodeling complex RSC, which is required for the establishment of sister chromatid cohesion.
A novel mode of chaperone action: heme activation of Hap1 by enhanced association of Hsp90 with the repressed Hsp70-Hap1 complex.
Navigating the chaperone network: an integrative map of physical and genetic interactions mediated by the hsp90 chaperone.
A two-hybrid screen of the yeast proteome for Hsp90 interactors uncovers a novel Hsp90 chaperone requirement in the activity of a stress-activated mitogen-activated protein kinase, Slt2p (Mpk1p).
The phosphatase Ppt1 is a dedicated regulator of the molecular chaperone Hsp90.
Proteome survey reveals modularity of the yeast cell machinery.
The molecular chaperone Hsp90 is required for high osmotic stress response in Saccharomyces cerevisiae.
Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
Crystal structure of an Hsp90-nucleotide-p23/Sba1 closed chaperone complex.
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Crystal structure of full-length Hsp82 dimer in closed conformation with SBA1 and ATP
"Here we present the crystal structure of full-length yeast Hsp90 in complex with an ATP analogue and the co-chaperone p23/Sba1."
The hsp90 molecular chaperone modulates multiple telomerase activities.
Molecular chaperone Hsp90 stabilizes Pih1/Nop17 to maintain R2TP complex activity that regulates snoRNA accumulation.
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HSP82/Hsp90 stabilizes Pih1/Nop17 to maintain R2TP complex activity that regulates snoRNA accumulation, providing IMP evidence for box C/D snoRNP assembly involvement.
"Together with the Tah1 cofactor, Hsp90 functions to stabilize Pih1. As a consequence, the chaperone is shown to affect box C/D accumulation and maintenance, especially under stress conditions."
High-quality binary protein interaction map of the yeast interactome network.
Structural and functional coupling of Hsp90- and Sgt1-centred multi-protein complexes.
Structural and functional analysis of SGT1-HSP90 core complex required for innate immunity in plants.
An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell.
Hsp90 is regulated by a switch point in the C-terminal domain.
Dynamics of heat shock protein 90 C-terminal dimerization is an important part of its conformational cycle.
Mixed Hsp90-cochaperone complexes are important for the progression of the reaction cycle.
Combinatorial depletion analysis to assemble the network architecture of the SAGA and ADA chromatin remodeling complexes.
HSP90 controls SIR2 mediated gene silencing.
Structural analysis of the interaction between Hsp90 and the tumor suppressor protein p53.
CDK-dependent Hsp70 Phosphorylation controls G1 cyclin abundance and cell-cycle progression.
Integration of the accelerator Aha1 in the Hsp90 co-chaperone cycle.
High-resolution structural analysis shows how Tah1 tethers Hsp90 to the R2TP complex.
Structural basis for phosphorylation-dependent recruitment of Tel2 to Hsp90 by Pih1.
Systematic Mutant Analyses Elucidate General and Client-Specific Aspects of Hsp90 Function.
Detection of protein-protein interactions at the septin collar in Saccharomyces cerevisiae using a tripartite split-GFP system.
The role of structural pleiotropy and regulatory evolution in the retention of heteromers of paralogs.
A Single Site Phosphorylation on Hsp82 Ensures Cell Survival during Starvation in Saccharomyces cerevisiae.
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Single-site phosphorylation on HSP82 governs nuclear redistribution during starvation; supports both cytoplasmic and nuclear pools of HSP82.
"Ppt1 regulates Hsp82 distribution in the cytoplasm and nucleus by dephosphorylating the S485 residue on Hsp82."
The social and structural architecture of the yeast protein interactome.
In vivo functions of the Saccharomyces cerevisiae Hsp90 chaperone.
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In vivo demonstration of protein folding and refolding functions
"The data suggest that Hsp90 is not required for the de novo folding of most proteins, but it is required for a specific subset of proteins that have greater difficulty reaching their native conformations."
Molecular mechanism governing heme signaling in yeast: a higher-order complex mediates heme regulation of the transcriptional activator HAP1.
In vivo function of Hsp90 is dependent on ATP binding and ATP hydrolysis.
Cns1 is an essential protein associated with the hsp90 chaperone complex in Saccharomyces cerevisiae that can restore cyclophilin 40-dependent functions in cpr7Delta cells.
hsp82 is an essential protein that is required in higher concentrations for growth of cells at higher temperatures.
Falcon deep research report on yeast HSP82 (Hsp90)
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Hsp82 is an ATP-dependent molecular chaperone that assists late-stage folding, activation,
and stability of a defined set of specific client proteins, acting as a selective proteostasis
hub rather than a general chaperone for all misfolded proteins.
"Hsp82 (Hsp90) is an **ATP-dependent molecular chaperone** that assists the **late-stage folding, activation, and stability** of a large set of specific “client” proteins (substrates), including many signaling regulators (notably protein kinases and transcription factors)."
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Yeast Hsp90 (Hsp82/Hsc82) is a dimeric chaperone cycling between an open, C-terminally
dimerized state and an ATP-induced closed state with additional N-terminal contacts, regulated
by co-chaperones.
"Yeast Hsp90 (Hsp82/Hsc82) is a **dimeric** chaperone cycling between:
- an **open** state (C-terminally dimerized) and
- an **ATP-induced closed** state with additional N-terminal contacts."
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Yeast has approximately 14 Hsp90 co-chaperones that target clients, modulate ATPase activity,
and stabilize or destabilize conformational states; Sti1/Hop targets clients to open Hsp90,
Sba1/p23 stabilizes closed states, Aha1 stimulates ATP hydrolysis, and Cdc37 targets kinases.
"Yeast has ~14 Hsp90 co-chaperones (diverse domain architectures) that **target clients**, **modulate ATPase activity**, and **stabilize or destabilize** conformational states:"
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HSP82 is the heat-inducible cytosolic Hsp90 isoform: very low at 25-30C and induced at 37C to
levels similar to the constitutive Hsc82, consistent with a stress-specialized role.
"**Hsp82 is very low at 25–30°C and induced at 37°C to levels similar to Hsc82**, consistent with a stress-specialized role."
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Hsp82 is more thermally stable than Hsc82 (Tm ~60.4C vs 57.1C) and shows superior refolding
(~29% vs ~14% full refolding events in single-molecule assays), while Hsc82 has somewhat
higher ATPase activity, reflecting isoform specialization mapping to the N-terminal domain.
"Hsp82 is **more thermally stable** than Hsc82 (Tm ~60.4°C vs 57.1°C). (girstmair2019thehsp90isoforms pages 1-2, girstmair2019thehsp90isoforms media 00261b28)"
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Hsp90 is required for basal and pheromone-induced MAPK signaling in yeast, with Ste11
(the yeast Raf-equivalent MAPKKK) identified as a key endogenous client/substrate required
for pathway accumulation and function.
"**MAPK/pheromone signaling:** Hsp90 is required for basal and pheromone-induced MAPK signaling, with **Ste11 (yeast Raf-equivalent MAPKKK)** identified as a key endogenous Hsp90 client/substrate required for accumulation and pathway function."
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The HSP82/HSC82 family is essential: single deletion is viable but double disruption is
lethal, and at least one cytosolic Hsp90 isoform is required for viability.
"Classic yeast genetics and biochemistry established that the HSP82/HSC82 family is **essential** (double disruption lethal), and that Hsp90 supports key signaling regulators."
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Cytosolic Hsp90 (Hsp82/Hsc82) is broadly distributed during vegetative growth but
accumulates in the nucleus in quiescent cells (glucose exhaustion) and in sporulating
diploids, where nuclear accumulation defects correlate with sporulation/spore-wall defects.
"**Condition-dependent nuclear accumulation:** A key cell-biological finding is that Hsp90 (and the cochaperone Sba1/p23) **accumulates in the nucleus in quiescent cells (glucose exhaustion)** and in sporulating diploids; nuclear accumulation defects correlate with **sporulation/spore-wall defects**, and pharmacological inhibition (macbecin) similarly disrupts nuclear accumulation and spore development."