AT5G52640

UniProt ID: P27323
Organism: Arabidopsis thaliana
Review Status: INITIALIZED
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Gene Description

HSP90.1 is a stress-inducible cytosolic Hsp90 chaperone of Arabidopsis thaliana. It binds and hydrolyzes ATP and has both holdase and ATP-dependent foldase activity. With cochaperones such as ROF1, RAR1 and SGT1 it supports client-protein function, heat acclimation and innate immune signaling; hsp90.1 mutations compromise RPS2-mediated antibacterial resistance. HSP90.1 has cytoplasmic and heat-induced nuclear pools and associates with plasma-membrane client machinery. It interacts with ABCB1 and contributes to the stability and regulation of auxin-transporter systems. HSP90.1 can also enhance COP1–ELF3 association, providing a protein-interaction contribution to developmental regulation; combined cytosolic-HSP90 experiments connect this module to dark- and warm-temperature hypocotyl growth.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0006457 protein folding
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 participates directly in protein folding.
Reason: Direct target holdase and ATP-dependent foldase assays support the broad process. Protein folding is a central chaperone function; specificity for selected clients does not make the parent process non-core.
Supporting Evidence:
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0016887 ATP hydrolysis activity
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 has intrinsic ATP hydrolysis activity.
Reason: The biochemical comparison measures intrinsic ATPase activity for the target. Lower activity than HSP90.3 does not negate catalysis; ATP hydrolysis supports the chaperone conformational cycle.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0032991 protein-containing complex
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 forms protein complexes with clients and cochaperones.
Reason: Actual positive PAINT descent is verified, and ROF1/HSP90.1 plus client co-immunoprecipitation provide direct corroboration. A broad complex term remains correct.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
PMID:26230318
HSP90 was successfully detected in AtPolλ immunoprecipitates from tobacco leaf tissues ectopically expressing AtPolλ-TAP and AtHSP90.1-TAP under the CaMV-35S promoter
GO:0005886 plasma membrane
IBA
GO_REF:0000033
ACCEPT
Summary: A plasma-membrane-associated HSP90 pool is supported.
Reason: Retain the inherited and experimentally curated location. Peripheral membrane association does not require a transmembrane helix or covalent lipid anchor. PMID:17644812 used washed enriched plasma-membrane fractions, and the later TWD1/ABCB work gives target-specific membrane-client context. Proteomics does not establish that all HSP90.1 is membrane resident.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
Figure 2e reports ABCB1 co-immunoprecipitation with both HSP90.1 and HSP90.3.
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
stabilizing plasma-membrane ABCB auxin transporters
GO:0005524 ATP binding
IBA
GO_REF:0000033
ACCEPT
Summary: ATP binding is intrinsic to the HSP90.1 chaperone cycle.
Reason: ATP-dependent foldase activity and conserved HSP90 ATPase chemistry support ATP/nucleotide binding. The broad nucleotide-binding term is true and central, not an erroneous annotation merely because ATP is more precise.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0005829 cytosol
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 has a cytoplasmic/cytosolic pool.
Reason: Cytosolic HSP90-family localization agrees with curated proteomic evidence and normal-condition ROF1–HSP90.1 localization. Additional nuclear or membrane-associated pools are compatible.
Supporting Evidence:
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0050821 protein stabilization
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 stabilizes client proteins.
Reason: Actual descent from the positive cytosolic-HSP90 node is consistent with target ABCB1 interaction, HSP90-dependent membrane-client stability and POLL chaperone association. Client stabilization is a central function.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
Figure 2e reports ABCB1 co-immunoprecipitation with both HSP90.1 and HSP90.3.
PMID:26230318
HSP90 was successfully detected in AtPolλ immunoprecipitates from tobacco leaf tissues ectopically expressing AtPolλ-TAP and AtHSP90.1-TAP under the CaMV-35S promoter
GO:0034605 cellular response to heat
IBA
GO_REF:0000033
ACCEPT
Summary: HSP90.1 contributes to the heat response.
Reason: Heat-inducible expression is consistent with active proteostasis and the heat-induced ROF1–HSP90.1 nuclear complex. The source IEP annotation is not recast as a biochemical assay.
Supporting Evidence:
PMID:19366428
Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0051082 unfolded protein binding
IBA
GO_REF:0000033
MODIFY
Summary: The retired unfolded-protein-binding term should be represented by chaperone activity.
Reason: QuickGO marks GO:0051082 obsolete and recommends a chaperone/holdase activity term. The target has both holdase and ATP-dependent foldase activity; the earlier claim that HSP90.1 cannot interact with unfolded clients was incorrect. MODIFY is retained for ontology migration, not biological rejection. ATP-dependent protein folding chaperone is already present among source annotations.
Propagation Review
Root cause: TERM SCOPING PROBLEM
Sources checked:
PANTHER:PTN000163527 SOURCE STALE OR MISSING
Actual target descent is verified. The current node retains ATPase, ATP-binding and protein-folding assertions, while obsolete GO:0051082 is absent. This is ontology retirement, not evidence of target loss or incorrect ancestral biology.
Supporting Evidence:
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
term retirement does not demonstrate loss of unfolded-protein recognition.
GO:0048471 perinuclear region of cytoplasm
IBA
GO_REF:0000033
ACCEPT
Summary: Retain the inherited perinuclear cytoplasmic pool.
Reason: The actual target descends from PTN000163629 carrying this location. A broadly cytosolic distribution and heat-induced nuclear movement do not exclude perinuclear cytoplasm. No target-specific loss or incompatible localization was established; the assertion remains phylogenetic rather than a newly claimed target imaging result.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
PMID:19366428
Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex
GO:0000166 nucleotide binding
IEA
GO_REF:0000043
ACCEPT
Summary: ATP binding is intrinsic to the HSP90.1 chaperone cycle.
Reason: ATP-dependent foldase activity and conserved HSP90 ATPase chemistry support ATP/nucleotide binding. The broad nucleotide-binding term is true and central, not an erroneous annotation merely because ATP is more precise.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
GO:0002376 immune system process
IEA
GO_REF:0000043
ACCEPT
Summary: HSP90.1 supports innate antibacterial defense.
Reason: Target hsp90.1 alleles reduce RPS2-mediated restriction of bacterial growth. The broad defense/immune terms correctly capture this established role; breadth is not a reason to demote them. HSP90.1 contributes chaperoning/regulatory work rather than being the substrate consumed by the defense process.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
AtHSP90.1 is required for full **RPS2-mediated resistance**
GO:0005524 ATP binding
IEA
GO_REF:0000120
ACCEPT
Summary: ATP binding is intrinsic to the HSP90.1 chaperone cycle.
Reason: ATP-dependent foldase activity and conserved HSP90 ATPase chemistry support ATP/nucleotide binding. The broad nucleotide-binding term is true and central, not an erroneous annotation merely because ATP is more precise.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
GO:0005737 cytoplasm
IEA
GO_REF:0000044
ACCEPT
Summary: HSP90.1 has a cytoplasmic/cytosolic pool.
Reason: Cytosolic HSP90-family localization agrees with curated proteomic evidence and normal-condition ROF1–HSP90.1 localization. Additional nuclear or membrane-associated pools are compatible.
Supporting Evidence:
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0006457 protein folding
IEA
GO_REF:0000002
ACCEPT
Summary: HSP90.1 participates directly in protein folding.
Reason: Direct target holdase and ATP-dependent foldase assays support the broad process. Protein folding is a central chaperone function; specificity for selected clients does not make the parent process non-core.
Supporting Evidence:
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
GO:0006952 defense response
IEA
GO_REF:0000043
ACCEPT
Summary: HSP90.1 supports innate antibacterial defense.
Reason: Target hsp90.1 alleles reduce RPS2-mediated restriction of bacterial growth. The broad defense/immune terms correctly capture this established role; breadth is not a reason to demote them. HSP90.1 contributes chaperoning/regulatory work rather than being the substrate consumed by the defense process.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
AtHSP90.1 is required for full **RPS2-mediated resistance**
GO:0016887 ATP hydrolysis activity
IEA
GO_REF:0000002
ACCEPT
Summary: HSP90.1 has intrinsic ATP hydrolysis activity.
Reason: The biochemical comparison measures intrinsic ATPase activity for the target. Lower activity than HSP90.3 does not negate catalysis; ATP hydrolysis supports the chaperone conformational cycle.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
GO:0045087 innate immune response
IEA
GO_REF:0000043
ACCEPT
Summary: HSP90.1 supports innate antibacterial defense.
Reason: Target hsp90.1 alleles reduce RPS2-mediated restriction of bacterial growth. The broad defense/immune terms correctly capture this established role; breadth is not a reason to demote them. HSP90.1 contributes chaperoning/regulatory work rather than being the substrate consumed by the defense process.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
AtHSP90.1 is required for full **RPS2-mediated resistance**
GO:0051082 unfolded protein binding
IEA
GO_REF:0000002
MODIFY
Summary: The retired unfolded-protein-binding term should be represented by chaperone activity.
Reason: QuickGO marks GO:0051082 obsolete and recommends a chaperone/holdase activity term. The target has both holdase and ATP-dependent foldase activity; the earlier claim that HSP90.1 cannot interact with unfolded clients was incorrect. MODIFY is retained for ontology migration, not biological rejection. ATP-dependent protein folding chaperone is already present among source annotations.
Supporting Evidence:
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
term retirement does not demonstrate loss of unfolded-protein recognition.
GO:0140662 ATP-dependent protein folding chaperone
IEA
GO_REF:0000002
ACCEPT
Summary: HSP90.1 is an ATP-dependent protein-folding chaperone.
Reason: Direct purified-target foldase and intrinsic ATPase observations support the domain-based electronic activity assignment.
Supporting Evidence:
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
GO:0005515 protein binding
IPI
PMID:19366428
Arabidopsis ROF1 (FKBP62) modulates thermotolerance by inter...
REMOVE
Summary: HSP90.1 physically associates with ROF1.
Reason: Remove the generic protein-binding annotation because it does not describe a specific molecular function. The interaction evidence and source attribution are retained; this curation action does not assert that the reported association is false. The inspected evidence does not justify an informative replacement function for this particular row.
Supporting Evidence:
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
GO:0009505 plant-type cell wall
HDA
PMID:16287169
Arabidopsis cell wall proteome defined using multidimensiona...
UNDECIDED
Summary: Cell-wall detection remains unresolved at the exact target/compartment level.
Reason: The HDA source is a purified-cell-wall proteomics study. Its abstract-only cache cannot establish the target peptide mapping, extracellular retention or co-purification controls, so a confident contamination claim was not justified. Lack of a classical secretory signal does not by itself exclude a cell-wall-associated pool. Retain UNDECIDED pending the full target-resolved data.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
For the cell-wall HDA from PMID:16287169, the abstract does not resolve target-specific peptide attribution or distinguish an extracellular pool from co-purification.
GO:0005886 plasma membrane
HDA
PMID:17644812
A high content in lipid-modified peripheral proteins and int...
ACCEPT
Summary: A plasma-membrane-associated HSP90 pool is supported.
Reason: Retain the inherited and experimentally curated location. Peripheral membrane association does not require a transmembrane helix or covalent lipid anchor. PMID:17644812 used washed enriched plasma-membrane fractions, and the later TWD1/ABCB work gives target-specific membrane-client context. Proteomics does not establish that all HSP90.1 is membrane resident.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
Figure 2e reports ABCB1 co-immunoprecipitation with both HSP90.1 and HSP90.3.
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
stabilizing plasma-membrane ABCB auxin transporters
GO:0005515 protein binding
IPI
PMID:25358503
Characterization of a Novel DWD protein that participates in...
REMOVE
Summary: HSP90.1 physically associates with HTD1.
Reason: Remove the generic protein-binding annotation because it does not describe a specific molecular function. The interaction evidence and source attribution are retained; this curation action does not assert that the reported association is false. The inspected evidence does not justify an informative replacement function for this particular row.
Supporting Evidence:
PMID:25358503
HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo
GO:0005829 cytosol
HDA
PMID:25293756
A proteomic strategy for global analysis of plant protein co...
ACCEPT
Summary: HSP90.1 has a cytoplasmic/cytosolic pool.
Reason: Cytosolic HSP90-family localization agrees with curated proteomic evidence and normal-condition ROF1–HSP90.1 localization. Additional nuclear or membrane-associated pools are compatible.
Supporting Evidence:
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0005737 cytoplasm
ISM
GO_REF:0000122
ACCEPT
Summary: HSP90.1 has a cytoplasmic/cytosolic pool.
Reason: Cytosolic HSP90-family localization agrees with curated proteomic evidence and normal-condition ROF1–HSP90.1 localization. Additional nuclear or membrane-associated pools are compatible.
Supporting Evidence:
PMID:19366428
ROF1 binds heat shock proteins HSP90.1 via its tetratricopeptide repeat domain
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
The actual PTHR11528 PAINT tree places leaf PTN000163824 below root PTN000163527 and cytosolic-HSP90 node PTN000163629.
GO:0005515 protein binding
IPI
PMID:26230318
Understanding the Physical and Molecular Basis of Stability ...
REMOVE
Summary: HSP90.1 physically associates with POLL.
Reason: Remove the generic protein-binding annotation because it does not describe a specific molecular function. The interaction evidence and source attribution are retained; this curation action does not assert that the reported association is false. The inspected evidence does not justify an informative replacement function for this particular row.
Supporting Evidence:
PMID:26230318
HSP90 was successfully detected in AtPolλ immunoprecipitates from tobacco leaf tissues ectopically expressing AtPolλ-TAP and AtHSP90.1-TAP under the CaMV-35S promoter
GO:0006457 protein folding
IDA
PMID:23827697
Structural and functional differences of cytosolic 90-kDa he...
ACCEPT
Summary: HSP90.1 participates directly in protein folding.
Reason: Direct target holdase and ATP-dependent foldase assays support the broad process. Protein folding is a central chaperone function; specificity for selected clients does not make the parent process non-core.
Supporting Evidence:
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
PMID:23827697
ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
GO:0005515 protein binding
IPI
PMID:14504384
HSP90 interacts with RAR1 and SGT1 and is essential for RPS2...
REMOVE
Summary: Retain the curated HSP90 interaction evidence involving the immune cochaperone network.
Reason: Remove the generic protein-binding annotation because it does not describe a specific molecular function. The interaction evidence and source attribution are retained; this curation action does not assert that the reported association is false. The inspected evidence does not justify an informative replacement function for this particular row.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
cochaperones **RAR1** and **SGT1**
GO:0005515 protein binding
IPI
PMID:17148606
RAR1, a central player in plant immunity, is targeted by Pse...
UNDECIDED
Summary: Retain the curated HSP90 interaction evidence involving the immune cochaperone network.
Reason: The curated interaction is not contradicted, but the accessible evidence does not expose the target-specific assay needed to choose a more informative molecular function. Leave this row unresolved pending source inspection; generic protein binding is not accepted as a functional synthesis, and lack of accessible assay detail is not evidence that the interaction is false.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
cochaperones **RAR1** and **SGT1**
GO:0042742 defense response to bacterium
IMP
PMID:14504384
HSP90 interacts with RAR1 and SGT1 and is essential for RPS2...
ACCEPT
Summary: HSP90.1 supports innate antibacterial defense.
Reason: Target hsp90.1 alleles reduce RPS2-mediated restriction of bacterial growth. The broad defense/immune terms correctly capture this established role; breadth is not a reason to demote them. HSP90.1 contributes chaperoning/regulatory work rather than being the substrate consumed by the defense process.
Supporting Evidence:
PMID:14504384
both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi
file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
AtHSP90.1 is required for full **RPS2-mediated resistance**
GO:0046685 response to arsenic-containing substance
IEP
PMID:16668895
Isolation and analysis of the expression of two genes for th...
KEEP AS NON CORE
Summary: Arsenite induces HSP90.1 expression.
Reason: Retain the source IEP stress-response observation as non-core because the evidence establishes induction rather than a specific arsenic-handling activity. This does not deny participation in stress proteostasis or treat a broad term as intrinsically false.
Supporting Evidence:
PMID:16668895
arsenite stress strongly stimulated the accumulation of each mRNA in a coordinated fashion.
GO:0009408 response to heat
IEP
PMID:16668895
Isolation and analysis of the expression of two genes for th...
ACCEPT
Summary: HSP90.1 contributes to the heat response.
Reason: Heat-inducible expression is consistent with active proteostasis and the heat-induced ROF1–HSP90.1 nuclear complex. The source IEP annotation is not recast as a biochemical assay.
Supporting Evidence:
PMID:19366428
Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex
PMID:23827697
AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
GO:0005634 nucleus
IDA
PMID:19366428
Arabidopsis ROF1 (FKBP62) modulates thermotolerance by inter...
NEW
Summary: Heat stress induces a nuclear HSP90.1 complex.
Reason: Retain the authored proposal with direct experimental evidence from PMID:19366428. It describes the product itself in a nuclear complex, is distinct from perinuclear cytoplasm, and is not inferred solely from a client localization.
Supporting Evidence:
PMID:19366428
Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex
GO:0010100 negative regulation of photomorphogenesis
IDA
PMID:36707919
HSP90s are required for hypocotyl elongation during skotomor...
NEW
Summary: HSP90.1 contributes to the COP1–ELF3 module that promotes dark-grown seedling development.
Reason: Retain this authored regulatory-process proposal with calibrated scope. An explicit HSP90.1 construct increases COP1–ELF3 association, and combined cytosolic-HSP90 perturbations connect this module to ELF3-dependent inhibition of hypocotyl elongation in darkness. HSP90.1 performs protein-interaction work in the repression machinery; this is more than necessity alone. The physiological assay does not isolate HSP90.1 from all paralogs, and direct PIF4 folding is not established. QuickGO comparators CUL4, CSN4 and SPA1 show that non-DNA-binding components of this machinery can carry the process.
Supporting Evidence:
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
HSP90.1 enhanced the interaction between COP1 and ELF3
file:ARATH/AT5G52640/AT5G52640-primary-scope.md
Growth phenotypes use RNAi against HSP90.1–4 or inhibitors

Core Functions

ATP-dependent folding and stabilization of client proteins, with additional holdase activity; supported by direct HSP90.1 biochemistry.

Supporting Evidence:
  • PMID:23827697
    ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1.
  • PMID:23827697
    AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity.
  • PMID:19366428
    Exposure to heat stress induces nuclear localization of the ROF1-HSP90.1 complex

Chaperone support of RPS2-mediated antibacterial defense through the immune cochaperone network; exact target loss-of-function establishes the physiological role without assigning every NLR as a directly tested client.

Supporting Evidence:
  • PMID:14504384
    both athsp90.1 - 1 and athsp90.1 - 2 mutations compromised RPS2 -dependent resistance, resulting in 5- to 20-fold more growth by 3 dpi

Client interaction and stabilization in the TWD1/ABCB auxin-transporter system. HSP90.1 has direct ABCB1 co-immunoprecipitation and target mutant evidence; detailed interface FRET and broad inhibitor effects have HSP90.3/family scope. ABCBs carry out auxin transport.

Directly Involved In:
Cellular Locations:
Supporting Evidence:
  • file:ARATH/AT5G52640/AT5G52640-primary-scope.md
    Figure 2e reports ABCB1 co-immunoprecipitation with both HSP90.1 and HSP90.3.
  • file:ARATH/AT5G52640/AT5G52640-deep-research-falcon.md
    through interaction with the immunophilin **TWD1**

HSP90.1 promotes COP1–ELF3 association in a module that relieves ELF3 repression of PIF4 expression during dark/warm growth. The direct target assay measures protein association, while the physiological perturbations reduce several cytosolic HSP90 paralogs. Direct PIF4 maturation is not established.

Supporting Evidence:
  • file:ARATH/AT5G52640/AT5G52640-primary-scope.md
    HSP90.1 enhanced the interaction between COP1 and ELF3

References

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Suggested Questions for Experts

Q: Can full text and peptide-level data for PMID:16287169 distinguish HSP90.1 cell-wall localization from shared-paralog peptides or co-purification?

Q: Which TIR1/ZTL and developmental outputs are supported by exact HSP90.1 experiments or well-grounded paralog-specific inference, beyond combined cytosolic-HSP90 perturbations?

Q: Does HSP90.1 leave the completed COP1–ELF3 complex, satisfying the finished-complex scope of chaperone-mediated protein complex assembly?

Q: What term best represents HSP90.1 regulation of ABCB transporter stability and auxin distribution without assigning it the transport reaction?

Deep Research

Falcon

(AT5G52640-deep-research-falcon.md)

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Perplexity

(AT5G52640-deep-research-perplexity.md)

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📚 Additional Documentation

Notes

(AT5G52640-notes.md)

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Primary Scope

(AT5G52640-primary-scope.md)

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📄 View Raw YAML

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