CDC37

UniProt ID: P06101
Organism: Saccharomyces cerevisiae
Review Status: COMPLETE
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Gene Description

CDC37 encodes an essential cytosolic Hsp90 co-chaperone that specializes the Hsp90 system for protein kinase clients. Cdc37 binds protein kinases and Hsp90, promotes Hsp90-kinase complex formation, protects nascent kinase chains from rapid degradation, and supports post-translational kinase maturation. Its client effects explain downstream roles in Cdc28/Cak1-dependent cell-cycle progression, MAP kinase signaling, osmotic and cell wall stress responses, and spindle pole body duplication, but the core function is kinase-specific chaperone/adaptor activity rather than those downstream pathways themselves.

Existing Annotations Review

GO Term Evidence Action Reason
GO:0005737 cytoplasm
IBA
GO_REF:0000033
ACCEPT
Summary: The phylogenetic cytoplasm annotation is consistent with experimental localization and with Cdc37 acting in cytosolic Hsp90-kinase complexes.
Reason: Cdc37 is experimentally detected in the cytoplasm and its core Hsp90 co-chaperone activity is carried out in the cytosolic chaperone machinery.
Supporting Evidence:
PMID:14562095
Global analysis of protein localization in budding yeast.
file:yeast/CDC37/CDC37-deep-research-falcon.md
Cdc37's functional locale is best described as the cytosolic chaperone machinery, where it forms transient Cdc37-kinase and Hsp90-Cdc37-kinase complexes.
GO:0006457 protein folding
IBA
GO_REF:0000033
ACCEPT
Summary: Cdc37 is a kinase-directed Hsp90 co-chaperone required for productive folding and maturation of protein kinases.
Reason: Although Cdc37 is not a general foldase for all proteins, the annotation accurately captures its core role in protein kinase folding/maturation in the Hsp90 pathway.
Supporting Evidence:
PMID:17242065
Cdc37 functions at distinct steps in kinase biogenesis that involves protecting nascent chains from rapid degradation followed by its folding function in association with Hsp90.
file:yeast/CDC37/CDC37-deep-research-falcon.md
Cdc37 selectively recognizes kinase clients and promotes their stabilization and productive engagement with Hsp90 to achieve folding/maturation and functional activation.
GO:0031072 heat shock protein binding
IBA
GO_REF:0000033
ACCEPT
Summary: The annotation reflects the well-established physical and functional interaction between Cdc37 and Hsp90.
Reason: Hsp90 binding is central to Cdc37 function as a kinase-targeting adaptor and is supported by biochemical and genetic evidence for Hsp90-Cdc37-kinase complexes.
Supporting Evidence:
PMID:9242486
The identification of Cdc37 as the 50-kD protein in several Hsp90-kinase complexes, together with other data, led to the recent suggestion that Cdc37 is a kinase-targeting "subunit" of Hsp90.
PMID:17220467
The interaction of Hsp90, Slt2p, and Hog1p with Cdc37p depends on the phosphorylation status of Cdc37p.
GO:0050821 protein stabilization
IBA
GO_REF:0000033
ACCEPT
Summary: Protein stabilization is a core biological process for Cdc37, specifically stabilization of protein kinase clients.
Reason: Multiple studies show that Cdc37 maintains kinase abundance and protects newly synthesized kinases from degradation.
Supporting Evidence:
PMID:17242065
showed that 51 had decreased abundance compared with levels in the wild-type strain.
file:yeast/CDC37/CDC37-deep-research-falcon.md
In a panel of 65 kinases, 51 showed decreased abundance in a cdc37 mutant, supporting a broad role in kinase homeostasis.
GO:0051082 unfolded protein binding
IBA
GO_REF:0000033
MODIFY
Summary: Cdc37 does bind non-native kinase clients, but the broad "unfolded protein binding" term obscures the kinase-specific co-chaperone mechanism.
Reason: Replace the generic binding term with protein-folding chaperone activity; kinase client binding is already captured by the accepted GO:0019901 annotation.
Proposed replacements: protein folding chaperone
Supporting Evidence:
PMID:17242065
Cdc37 protects nascent kinase chains from rapid degradation shortly after synthesis.
GO:0051087 protein-folding chaperone binding
IBA
GO_REF:0000033
ACCEPT
Summary: This term captures Cdc37 binding to the Hsp90 chaperone machinery.
Reason: Protein-folding chaperone binding is a core molecular interaction for Cdc37, which couples kinase clients to Hsp90.
Supporting Evidence:
PMID:9242486
the very similar chaperone activities of the two proteins, uncovered through in vitro analysis, diverge in vivo in specific signal transduction pathways.
GO:0005737 cytoplasm
IEA
GO_REF:0000044
ACCEPT
Summary: UniProtKB subcellular-location mapping to cytoplasm is correct.
Reason: The automated cytoplasm annotation agrees with the experimental localization and the cytosolic Hsp90 co-chaperone function.
Supporting Evidence:
UniProt:P06101
SUBCELLULAR LOCATION: Cytoplasm.
GO:0019901 protein kinase binding
IEA
GO_REF:0000002
ACCEPT
Summary: InterPro-derived protein kinase binding is highly specific and captures the key client-recognition activity of Cdc37.
Reason: Cdc37 is a kinase-targeting co-chaperone, and protein kinase binding is the most informative currently annotated molecular function for its client specificity.
Supporting Evidence:
UniProt:P06101
Co-chaperone that binds to numerous kinases and promotes their interaction with the Hsp90 complex, resulting in their stabilization.
file:yeast/CDC37/CDC37-deep-research-falcon.md
Cdc37 selectively recognizes kinase clients and promotes their stabilization and productive engagement with Hsp90.
GO:0051301 cell division
IEA
GO_REF:0000043
KEEP AS NON CORE
Summary: Cell division is a true consequence of Cdc37 activity through Cdc28/Cak1 and spindle-pole-body kinase clients, but it is not the molecular core function of Cdc37.
Reason: Retain as a supported downstream biological process while keeping the core function focused on kinase-specific chaperoning and stabilization.
Supporting Evidence:
PMID:7753858
Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.
file:yeast/CDC37/CDC37-deep-research-falcon.md
CDC37 is essential for G1/Start progression and for activation of the major cyclin-dependent kinase Cdc28.
GO:0005515 protein binding
IPI
PMID:15766533
Navigating the chaperone network: an integrative map of phys...
MARK AS OVER ANNOTATED
Summary: This high-throughput interaction annotation is real evidence of physical interactions but the term is too generic for Cdc37.
Reason: Protein binding does not distinguish Cdc37's specific Hsp90/kinase co-chaperone role; specific kinase and chaperone binding annotations are more informative.
GO:0005515 protein binding
IPI
PMID:15879519
A two-hybrid screen of the yeast proteome for Hsp90 interact...
MARK AS OVER ANNOTATED
Summary: The interaction evidence supports Hsp90 pathway biology but the generic protein binding term is uninformative.
Reason: Use specific Hsp90/chaperone and kinase-client terms rather than generic protein binding for Cdc37.
GO:0005515 protein binding
IPI
PMID:16554755
Global landscape of protein complexes in the yeast Saccharom...
MARK AS OVER ANNOTATED
Summary: Large-scale complex data document interactions but do not by themselves define a specific molecular function.
Reason: Generic protein binding is over-annotated for a co-chaperone whose specific binding modes are captured by protein kinase binding and protein-folding chaperone binding.
GO:0005515 protein binding
IPI
PMID:19536198
An atlas of chaperone-protein interactions in Saccharomyces ...
MARK AS OVER ANNOTATED
Summary: The chaperone-protein interaction atlas supports Cdc37 involvement in the chaperone network, but the GO term is too broad.
Reason: The annotation should not be treated as core because more specific chaperone and kinase-client binding terms describe the function.
GO:0005737 cytoplasm
HDA
PMID:14562095
Global analysis of protein localization in budding yeast.
ACCEPT
Summary: High-throughput localization to cytoplasm agrees with the known site of Cdc37-Hsp90 kinase-chaperone action.
Reason: Cytoplasm is a supported core cellular component for Cdc37.
GO:0043410 positive regulation of MAPK cascade
IMP
PMID:17220467
Cdc37p is required for stress-induced high-osmolarity glycer...
KEEP AS NON CORE
Summary: Cdc37 positively affects HOG and PKC MAPK pathway output by stabilizing and interacting with Hog1 and Slt2.
Reason: This is well-supported pathway-level biology but is downstream of the core kinase-chaperone function.
Supporting Evidence:
PMID:17220467
levels of the MAPKs Hog1p and Slt2p (Mpk1p) in cells are reduced in a cdc37-S14A mutant
GO:0071474 cellular hyperosmotic response
IMP
PMID:17220467
Cdc37p is required for stress-induced high-osmolarity glycer...
KEEP AS NON CORE
Summary: The hyperosmotic-response phenotype is supported by cdc37-S14A effects on Hog1/Hsp90/Cdc37 interactions.
Reason: Retain as a valid stress-response annotation, but do not elevate it above the kinase-specific chaperone role.
Supporting Evidence:
PMID:17220467
Mutation of the phosphorylation site Ser14 in Cdc37p renders cells sensitive to osmotic stress.
GO:0071852 fungal-type cell wall organization or biogenesis
IMP
PMID:17220467
Cdc37p is required for stress-induced high-osmolarity glycer...
KEEP AS NON CORE
Summary: Cdc37 affects cell wall stress responses through the Slt2/PKC MAPK pathway.
Reason: This is a supported downstream pathway consequence of kinase chaperoning, not the core molecular role.
Supporting Evidence:
PMID:17220467
during cell wall stress, the interaction of Slt2p with Cdc37p and Hsp90 is crucial for Slt2p-dependent downstream responses
GO:0038066 p38MAPK cascade
IPI
PMID:17220467
Cdc37p is required for stress-induced high-osmolarity glycer...
KEEP AS NON CORE
Summary: In yeast this annotation reflects Hog1 MAPK interaction and pathway support by Cdc37.
Reason: The physical interaction is relevant but represents a client/pathway context rather than the core function of Cdc37.
Supporting Evidence:
PMID:17220467
Hog1p and Slt2p both interact in a complex with Cdc37p in vivo.
GO:0071474 cellular hyperosmotic response
IPI
PMID:17220467
Cdc37p is required for stress-induced high-osmolarity glycer...
KEEP AS NON CORE
Summary: Interaction with Hog1 supports Cdc37 participation in osmotic stress signaling.
Reason: The annotation is valid as pathway context but should remain non-core relative to the kinase-chaperone activity.
Supporting Evidence:
PMID:17220467
the osmosensitive phenotype of the cdc37-S14A mutant is due to the loss of the interaction between Cdc37p, Hog1p, and Hsp90.
GO:0030474 spindle pole body duplication
IMP
PMID:9060463
The yeast CDC37 gene interacts with MPS1 and is required for...
KEEP AS NON CORE
Summary: Cdc37 is required for proper spindle pole body duplication, likely through kinase-client biology involving Mps1.
Reason: Retain as a supported cell-cycle phenotype, but classify as non-core because it is downstream of Cdc37's kinase-chaperone role.
Supporting Evidence:
PMID:9060463
The yeast CDC37 gene interacts with MPS1 and is required for proper execution of spindle pole body duplication.
GO:0050821 protein stabilization
IMP
PMID:17242065
Cdc37 has distinct roles in protein kinase quality control t...
ACCEPT
Summary: This annotation directly captures the experimentally demonstrated role of Cdc37 in kinase abundance and nascent-chain quality control.
Reason: Protein stabilization of kinase clients is central to Cdc37 function.
Supporting Evidence:
PMID:17242065
Results from our pulse-labeling studies showed that Cdc37 protects nascent kinase chains from rapid degradation shortly after synthesis.
GO:0051082 unfolded protein binding
IDA
PMID:9242486
Cdc37 is a molecular chaperone with specific functions in si...
MODIFY
Summary: The experiment supports molecular chaperone activity, but the GO term is too generic for Cdc37's kinase-directed function.
Reason: Replace generic unfolded protein binding with protein folding chaperone, while leaving protein kinase binding to the existing accepted GO:0019901 annotation.
Proposed replacements: protein folding chaperone
Supporting Evidence:
PMID:9242486
In vitro, Cdc37 maintains denatured beta-galactosidase in an activation-competent state without reactivating it and stabilizes mature, but unstable, casein kinase II.
GO:0051726 regulation of cell cycle
IMP
PMID:7753858
Cdc37 is required for association of the protein kinase Cdc2...
KEEP AS NON CORE
Summary: Cdc37 regulates cell-cycle progression through effects on the cyclin- dependent kinase Cdc28.
Reason: Cell-cycle regulation is an important downstream consequence of kinase chaperoning but should not be treated as the primary molecular function.
Supporting Evidence:
PMID:7753858
Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.

Core Functions

Cdc37 is the kinase-targeting adaptor of the cytosolic Hsp90 chaperone system. It binds nascent or unstable protein kinase clients, protects many kinases from rapid degradation, and promotes subsequent Hsp90-dependent maturation. This client-specific chaperone role explains broad effects on Cdc28/Cak1 cell-cycle control, MAPK signaling, and spindle-pole-body duplication without making those downstream pathways the core function.

Molecular Function:
protein kinase binding
Cellular Locations:
Supporting Evidence:
  • PMID:17242065
    showed that 51 had decreased abundance compared with levels in the wild-type strain.
  • PMID:17242065
    Cdc37 functions at distinct steps in kinase biogenesis that involves protecting nascent chains from rapid degradation followed by its folding function in association with Hsp90.
  • file:yeast/CDC37/CDC37-deep-research-falcon.md
    Cdc37 selectively recognizes kinase clients and promotes their stabilization and productive engagement with Hsp90 to achieve folding/maturation and functional activation.
  • file:interpro/panther/PTHR12800/PTHR12800-metadata.yaml
    PANTHER family PTHR12800 is named CDC37-RELATED and includes the HSP90 co-chaperone CDC37 subfamily.

Cdc37 has a kinase-directed chaperone/stabilizing activity: it protects nascent or unstable kinase clients and keeps them competent for subsequent Hsp90-dependent maturation. This captures the GO:0044183 replacement used for broad unfolded-protein-binding annotations without treating Cdc37 as a generic bulk-folding chaperone.

Molecular Function:
protein folding chaperone
Cellular Locations:
Supporting Evidence:
  • PMID:17242065
    Cdc37 protects nascent kinase chains from rapid degradation shortly after synthesis.
  • PMID:9242486
    In vitro, Cdc37 maintains denatured beta-galactosidase in an activation-competent state without reactivating it and stabilizes mature, but unstable, casein kinase II.

Cdc37 binds the Hsp90 protein-folding chaperone system and helps load kinase clients into Hsp90-containing maturation complexes. This Hsp90-binding adaptor role is an inseparable part of the core kinase co-chaperone mechanism.

Directly Involved In:
Cellular Locations:
Supporting Evidence:
  • PMID:9242486
    The identification of Cdc37 as the 50-kD protein in several Hsp90-kinase complexes, together with other data, led to the recent suggestion that Cdc37 is a kinase-targeting "subunit" of Hsp90.
  • PMID:17220467
    Hog1p and Slt2p both interact in a complex with Cdc37p in vivo.

References

Gene Ontology annotation through association of InterPro records with GO terms
Annotation inferences using phylogenetic trees
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
Global analysis of protein localization in budding yeast.
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).
Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
Cdc37p is required for stress-induced high-osmolarity glycerol and protein kinase C mitogen-activated protein kinase pathway functionality by interaction with Hog1p and Slt2p (Mpk1p).
  • Cdc37 supports HOG and PKC MAPK signaling by stabilizing/interacting with Hog1 and Slt2.
    "Levels of the MAPKs Hog1p and Slt2p in cells are reduced in a cdc37-S14A mutant, and downstream responses mediated by Hog1p and Slt2p are compromised."
Cdc37 has distinct roles in protein kinase quality control that protect nascent chains from degradation and promote posttranslational maturation.
  • Cdc37 broadly stabilizes the yeast kinome.
    "Analysis of 65 Saccharomyces cerevisiae protein kinases showed that 51 had decreased abundance compared with levels in the wild-type strain."
  • Cdc37 protects nascent kinase chains from rapid degradation.
    "Results from pulse-labeling studies showed that Cdc37 protects nascent kinase chains from rapid degradation shortly after synthesis."
An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell.
Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.
The yeast CDC37 gene interacts with MPS1 and is required for proper execution of spindle pole body duplication.
Cdc37 is a molecular chaperone with specific functions in signal transduction.
  • Cdc37 has intrinsic chaperone activity and stabilizes kinase clients.
    "In vitro, Cdc37 maintains denatured beta-galactosidase in an activation-competent state without reactivating it and stabilizes mature, but unstable, casein kinase II."
UniProt:P06101
UniProt entry for CDC37/Hsp90 co-chaperone Cdc37
  • UniProt summarizes Cdc37 as a kinase-binding Hsp90 co-chaperone.
    "Co-chaperone that binds to numerous kinases and promotes their interaction with the Hsp90 complex, resulting in their stabilization."
file:yeast/CDC37/CDC37-deep-research-falcon.md
Falcon deep research report for CDC37
  • Falcon synthesis supports kinase-specific Hsp90 co-chaperone function as the core role.
    "CDC37 encodes an essential cytosolic Hsp90 co-chaperone that acts as a kinase-targeting adaptor."
file:interpro/panther/PTHR12800/PTHR12800-metadata.yaml
PANTHER family PTHR12800 CDC37-related metadata
  • PTHR12800 places yeast Cdc37 in the conserved CDC37-related family.
    "PANTHER family PTHR12800 is named CDC37-RELATED and includes the HSP90 co-chaperone CDC37 subfamily."

Suggested Questions for Experts

Q: Which yeast kinase clients require Cdc37 primarily for nascent-chain stabilization versus later Hsp90-dependent maturation?

Q: Are there yeast stress conditions that shift Cdc37 client specificity beyond the kinases already surveyed by abundance and interaction assays?

Suggested Experiments

Experiment: Pulse-SILAC or equivalent time-resolved proteomics in phosphosite and temperature-sensitive cdc37 mutants, paired with kinase activity assays, to separate defects in kinase synthesis, stability, and maturation.

Hypothesis: Distinct kinase subclasses show different dependence on Cdc37 for nascent-chain stabilization versus post-translational maturation.

Type: quantitative proteomics

Deep Research

Falcon

(CDC37-deep-research-falcon.md)
Research Report: Functional Annotation of *Saccharomyces cerevisiae* **CDC37** (UniProt P06101) Falcon Edison Scientific Literature 23 citations 2026-05-04T11:26:48.361829

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research Report: Functional Annotation of Saccharomyces cerevisiae CDC37 (UniProt P06101)

0. Target verification (critical identity checks)

The provided UniProt record describes Cdc37, an Hsp90 co-chaperone (also called the kinase-targeting subunit/p50) from Saccharomyces cerevisiae S288c, encoded by CDC37 (systematic locus YDR168W). The retrieved yeast primary literature consistently describes S. cerevisiae Cdc37 as an essential factor for protein-kinase stability/maturation that functions with Hsp90 and is regulated by CK2-dependent phosphorylation at conserved N-terminal serines (Ser14/Ser17 in yeast), matching the functional and regulatory features in the UniProt description. This corpus did not contain an explicit statement linking the accession number P06101 to CDC37/YDR168W, so accession-level mapping is not independently cross-validated here; the functional identity and organism match are strong and yeast-specific. (farrell2000cdc37promotesthe pages 1-2, mandal2007cdc37hasdistinct pages 1-3, miyata2004ck2controlsmultiple pages 1-2, millson2014cdc37engagesin pages 1-2)

1. Key concepts and definitions (current understanding)

1.1 What Cdc37 is (definition)

Cdc37 is a protein-kinase–directed co-chaperone/adaptor in the cytosolic Hsp90 system. Rather than catalyzing a chemical reaction, Cdc37 selectively recognizes kinase clients and promotes their stabilization and productive engagement with Hsp90 to achieve folding/maturation and functional activation. (mandal2007cdc37hasdistinct pages 1-3, miyata2004ck2controlsmultiple pages 1-2)

1.2 Domain architecture and how domains map to function

A widely used mechanistic model assigns separable roles to Cdc37 domains:
- N-terminal domain/region: primary kinase-binding module; binds determinants in the kinase catalytic domain (often mapped to the N-lobe of kinases). (mandal2007cdc37hasdistinct pages 1-3, verba2017howhsp90and pages 4-6)
- Middle domain: major Hsp90-binding interface (binding Hsp90 N-terminal and/or middle domain depending on cycle state), helping recruit kinases into the Hsp90 cycle. (verba2017howhsp90and pages 4-6)
- C-terminal region: contributes to client interactions in some species/contexts; in yeast it can be partly dispensable in some experimental settings discussed in review literature. (verba2017howhsp90and pages 4-6)

A structural feature highlighted in expert review is that a conserved Cdc37 motif can mimic part of the kinase αC–β4 loop, stabilizing a partially unfolded kinase conformation that can be further remodeled by Hsp90, providing a physical rationale for kinase selectivity. (verba2017howhsp90and pages 4-6)

Supporting visual evidence: Verba & Agard (2017) provide a schematic of Cdc37 domain architecture and a model of the Hsp90–Cdc37–kinase cycle. (verba2017howhsp90and media 39c974c8, verba2017howhsp90and media fe609c0f)

1.3 Mechanistic role in the Hsp90 cycle (“client loading” and ATPase tuning)

A consistent mechanistic theme is that Cdc37 helps load kinases onto Hsp90 and can inhibit/arrest Hsp90 ATPase-coupled conformational progression during client loading (e.g., by blocking lid closure/NTD dimerization), thereby stabilizing intermediate complexes until the client is ready for productive folding steps. (guimaraes2022developmentofa pages 20-25, verba2017howhsp90and pages 4-6)

2. Primary molecular function in yeast

2.1 Core function: kinase stability and cell-cycle control through Cdc28 and Cak1

In budding yeast, CDC37 is essential for G1/Start progression and for activation of the major cyclin-dependent kinase Cdc28 (Cdk1). In the temperature-sensitive cdc37-1 mutant, Cdc28 shows multiple defects including reduced total protein and reduced activity; importantly, Cdc28 protein levels were reported as ~3–5-fold lower than wild type in cdc37-1. (farrell2000cdc37promotesthe pages 1-2)

Cdc37 also supports the stability/activity of the CDK-activating kinase Cak1. The same primary study reported that Cak1 levels and activity are reduced in cdc37-1, supporting the view that Cdc37 is a general kinase biogenesis factor with particularly strong effects on key cell-cycle kinases. (farrell2000cdc37promotesthe pages 1-2, farrell2000cdc37promotesthe pages 5-6)

2.2 Kinome-wide role (“kinome biogenesis”)

A large-scale analysis (sampling 65 yeast protein kinases, ~50% of the kinome) found that 51 kinases had decreased abundance in a cdc37 mutant background, supporting a broad role for Cdc37 in kinase quality control and kinome stability. The same work proposed a two-step model: (i) protection of newly synthesized kinases from rapid degradation and (ii) post-translational maturation with Hsp90. (mandal2007cdc37hasdistinct pages 1-3)

Independent yeast genetic/interaction work further supports broad kinase dependence on Cdc37 phosphorylation state: the nonphosphorylatable cdc37(S14A) allele is temperature sensitive and was reported to destabilize ~70% of the kinome (as summarized in yeast-focused work on Cak1–Cdc37 association). (millson2014cdc37engagesin pages 1-2)

3. Regulation and pathway integration

3.1 Phosphoregulation by CK2 and coupling to the Hsp90 cycle

A central regulatory input is casein kinase 2 (CK2)-dependent phosphorylation of Cdc37 at a conserved N-terminal serine (Ser13 in mammals; Ser14/Ser17 in yeast numbering discussed in yeast literature). CK2-dependent phosphorylation is described as essential for optimal engagement of Cdc37 with a wide set of protein kinases and for productive Hsp90–kinase complex formation, while certain Cdc37 mutants can retain Hsp90 binding but lose effective kinase handling. (miyata2004ck2controlsmultiple pages 1-2, millson2014cdc37engagesin pages 1-2)

This establishes CDC37 as a node by which CK2 can coordinately influence the stability and activity of many kinases through a chaperone-mediated mechanism. (miyata2004ck2controlsmultiple pages 1-2)

3.2 Osmoadaptation and MAPK pathway cross-talk (Kss1)

Beyond core cell-cycle kinases, CDC37 connects to signaling. In a study of osmoadaptation, the cdc37-34 mutant showed osmosensitivity not explained by canonical HOG signaling defects; instead, the filamentous growth MAPK module (Ste11/Ste7/Kss1) was implicated. Multicopy suppression identified KSS1 as a suppressor and Kss1 was shown to physically interact with Cdc37, supporting a model where Cdc37 modulates osmoadaptation via MAPK signaling and downstream cell-wall organization. (yang2007cdc37pisinvolved pages 1-2)

4. Subcellular localization and complexes (where the protein acts)

Cdc37’s functional locale is best described as the cytosolic chaperone machinery, where it forms transient Cdc37–kinase and Hsp90–Cdc37–kinase complexes. A notable mechanistic detail is that Cdc37 can be dimeric in solution but is often described as monomeric within the ternary Hsp90–Cdc37–client complex, consistent with a dynamic adaptor role during client processing. (mandal2007cdc37hasdistinct pages 1-3, verba2017howhsp90and pages 4-6)

5. Recent developments (prioritizing 2023–2024) and current applications

5.1 2023–2024 research directions in yeast Hsp90/co-chaperone biology

A 2023 review emphasizes S. cerevisiae as a premier system for dissecting the Hsp90/co-chaperone network using genetic tools, systematic interaction mapping, and proteomics, enabling inference of client dependencies and pathway integration for components such as Cdc37. This reflects current practice: using yeast to connect chaperone/co-chaperone perturbations to signaling outputs and drug responses. (Backe et al., 2023-09-01, https://doi.org/10.1042/ebc20220224) (backe2023saccharomycescerevisiaeas pages 12-13)

5.2 Real-world implementations: yeast as a screening platform for Hsp90–Cdc37 pathway inhibitors

Yeast systems are also used as functional screening platforms to identify small molecules that perturb the Hsp90–Cdc37 pathway, commonly employing Cdc37-dependent kinase clients (e.g., sensitized Cdc28 backgrounds) as readouts and orthogonal assays for PPI disruption versus direct Hsp90 inhibition. This illustrates translational relevance (tool compounds, antifungal/anticancer target discovery) while leveraging yeast genetics for mechanism-of-action deconvolution. (guimaraes2022developmentofa pages 1-8, guimaraes2022developmentofa pages 63-66)

6. Expert opinion and authoritative synthesis

A highly cited expert review frames the Hsp90–Cdc37 system as enabling kinases to traverse conformational/energetic barriers (e.g., maintaining partially unfolded, activation-competent intermediates) and highlights open mechanistic questions such as how remodeling steps are coordinated with ATPase timing and co-chaperone exchange. This perspective supports interpreting yeast CDC37 phenotypes as resulting from failures in client loading, conformational stabilization, and maturation timing, rather than a single static binding defect. (Verba & Agard, 2017-10-01, https://doi.org/10.1016/j.tibs.2017.07.002) (verba2017howhsp90and pages 4-6)

7. Key statistics and data points (from recent and classic studies)

  • Cdc28 abundance defect: Cdc28 protein levels are ~3–5× lower in the budding-yeast cdc37-1 mutant (linked to Start arrest and low Cdc28 activity). (Farrell & Morgan, 2000-02-01, https://doi.org/10.1128/mcb.20.3.749-754.2000) (farrell2000cdc37promotesthe pages 1-2)
  • Kinome-scale dependence: in a panel of 65 kinases (~50% of the yeast kinome), 51 showed decreased abundance in a cdc37 mutant. (Mandal et al., 2007-01-29, https://doi.org/10.1083/jcb.200604106) (mandal2007cdc37hasdistinct pages 1-3)
  • Phospho-mutant broad impact (yeast): cdc37(S14A) associated with destabilization of ~70% of the kinome (reported in yeast-focused work analyzing kinase interactions and stability). (millson2014cdc37engagesin pages 1-2)

8. Concise functional annotation statement (yeast CDC37 / UniProt P06101)

CDC37 encodes an essential cytosolic Hsp90 co-chaperone that acts as a kinase-targeting adaptor. Its primary molecular role is to protect newly synthesized kinases from degradation and promote their Hsp90-dependent maturation, thereby maintaining cellular kinase abundance and enabling signaling and cell-cycle progression (notably via Cdc28 and Cak1). CDC37 function is regulated by CK2-dependent phosphorylation of conserved N-terminal serines (Ser14/Ser17 in yeast), and CDC37 also contributes to stress and osmoadaptation signaling (e.g., via Kss1-associated MAPK module crosstalk). (farrell2000cdc37promotesthe pages 1-2, mandal2007cdc37hasdistinct pages 1-3, miyata2004ck2controlsmultiple pages 1-2, yang2007cdc37pisinvolved pages 1-2)

Evidence summary table

The following table consolidates identity, molecular function, regulation, pathways, quantitative evidence, and recent application themes.

Category Key points Key supporting sources with year, URL, and citation context id
Identity/domains - Target matches Saccharomyces cerevisiae Cdc37, an essential Hsp90 co-chaperone specialized for protein kinases.
- Domain organization is consistent with UniProt family/domain annotation: N-terminal kinase-binding region, middle Hsp90-binding region, and C-terminal region with less clearly defined but functionally contributing roles.
- Yeast papers describe a conserved N-terminus important for kinase binding and regulation, with species-specific phosphosites at Ser14/Ser17.
- Mandal et al., 2007, J Cell Biol — https://doi.org/10.1083/jcb.200604106 (mandal2007cdc37hasdistinct pages 1-3)
- Verba & Agard, 2017, Trends Biochem Sci — https://doi.org/10.1016/j.tibs.2017.07.002 (verba2017howhsp90and pages 4-6)
- Millson et al., 2014, Cell Stress Chaperones — https://doi.org/10.1007/s12192-014-0497-4 (millson2014cdc37engagesin pages 1-2, millson2014cdc37engagesin pages 8-9)
Core molecular function - Cdc37 is a kinase-targeting adaptor/co-chaperone that recruits unstable or inactive protein kinases to Hsp90 for maturation rather than catalyzing a chemical reaction.
- It protects nascent kinase chains from rapid degradation and then promotes post-translational maturation/folding with Hsp90.
- Mechanistically, Cdc37 can arrest/inhibit the Hsp90 ATPase cycle during client loading by preventing lid closure and N-terminal dimerization.
- Farrell & Morgan, 2000, Mol Cell Biol — https://doi.org/10.1128/mcb.20.3.749-754.2000 (farrell2000cdc37promotesthe pages 1-2, farrell2000cdc37promotesthe pages 5-6)
- Mandal et al., 2007, J Cell Biol — https://doi.org/10.1083/jcb.200604106 (mandal2007cdc37hasdistinct pages 1-3)
- Guimarães, 2022, thesis — URL not available in retrieved metadata (guimaraes2022developmentofa pages 20-25)
Key clients/pathways - Best-supported yeast clients include Cdc28/CDK1 and Cak1/CDK-activating kinase, whose stability/activity depend on Cdc37.
- Cdc37 broadly supports kinome biogenesis and influences signaling pathways including MAPK/cell-cycle/osmoadaptation modules; literature links it to Kss1 cross-talk control and broader MAPK regulation.
- Functional impact is strongest for protein kinases rather than non-kinase substrates.
- Farrell & Morgan, 2000, Mol Cell Biol — https://doi.org/10.1128/mcb.20.3.749-754.2000 (farrell2000cdc37promotesthe pages 1-2)
- Yang et al., 2007, FEMS Yeast Res — https://doi.org/10.1111/j.1567-1364.2007.00237.x (yang2007cdc37pisinvolved pages 12-12)
- Millson et al., 2014, Cell Stress Chaperones — https://doi.org/10.1007/s12192-014-0497-4 (millson2014cdc37engagesin pages 8-9)
Regulation/PTMs - CK2 phosphorylation is a central regulatory mechanism; yeast Cdc37 is phosphorylated at Ser14 (and also Ser17 is discussed in yeast-focused sources), promoting productive kinase handling.
- Nonphosphorylatable mutants impair kinase maturation and can destabilize much of the kinome.
- PP5/Ppt1-mediated dephosphorylation in the Hsp90 complex is part of the chaperone cycle and helps regulate client activation/release.
- Miyata & Nishida, 2004, Mol Cell Biol — https://doi.org/10.1128/mcb.24.9.4065-4074.2004 (miyata2004ck2controlsmultiple pages 1-2)
- Vaughan et al., 2008, Molecular Cell — https://doi.org/10.1016/j.molcel.2008.07.021 (boczek2015thematurationofa pages 20-24, boczek2015thematurationof pages 20-24)
- Millson et al., 2014, Cell Stress Chaperones — https://doi.org/10.1007/s12192-014-0497-4 (millson2014cdc37engagesin pages 1-2, millson2014cdc37engagesin pages 8-9)
Localization/complexes - Cdc37 acts in the cytosolic Hsp90 chaperone machinery, forming transient Cdc37–kinase and Hsp90–Cdc37–kinase complexes.
- In solution Cdc37 can dimerize, but evidence indicates it is often monomeric in the ternary Hsp90–Cdc37–client complex.
- Functional localization is therefore best understood as cytosolic proteostasis/signaling complexes rather than a membrane or organellar enzyme site.
- Mandal et al., 2007, J Cell Biol — https://doi.org/10.1083/jcb.200604106 (mandal2007cdc37hasdistinct pages 1-3)
- Verba & Agard, 2017, Trends Biochem Sci — https://doi.org/10.1016/j.tibs.2017.07.002 (verba2017howhsp90and pages 4-6)
- Boczek, 2015, thesis/review-like source — URL not available in retrieved metadata (boczek2015thematurationofa pages 20-24, boczek2015thematurationof pages 20-24)
Quantitative data - In a survey of 65 S. cerevisiae kinases (~50% of the kinome), 51 showed decreased abundance in a cdc37 mutant, supporting a broad role in kinase homeostasis.
- Review-level synthesis cited in the retrieved corpus estimates Cdc37/Hsp90 support for about ~75% of the yeast kinome and ~60% of the human kinome.
- Biophysical/structural summaries report weak Cdc37 dimerization (K_D ~80 µM) and species differences in Hsp90 ATPase rates (human ~20 min⁻¹ vs yeast ~1 min⁻¹).
- Mandal et al., 2007, J Cell Biol — https://doi.org/10.1083/jcb.200604106 (mandal2007cdc37hasdistinct pages 1-3)
- Boczek, 2015, thesis/review-like source — URL not available in retrieved metadata (boczek2015thematurationofa pages 20-24, boczek2015thematurationofa pages 15-20)
- Guimarães, 2022, thesis — URL not available in retrieved metadata (guimaraes2022developmentofa pages 20-25)
Recent developments/applications 2023-2024 - 2023 review emphasizes S. cerevisiae as a premier model for mapping Hsp90/co-chaperone interaction networks, genetic interactions, and drug responses relevant to Cdc37-dependent kinase control.
- 2024 yeast genetics further supports client/subnetwork specificity in Hsp90–cochaperone biology, reinforcing that distinct cochaperones regulate distinct client classes.
- Yeast-based screening platforms have been developed to identify Hsp90–Cdc37 pathway inhibitors, using cdc28-dependent sensitization and client depletion as functional readouts.
- Backe et al., 2023, Essays Biochem — https://doi.org/10.1042/ebc20220224 (backe2023saccharomycescerevisiaeas pages 12-13)
- Fulton et al., 2024, PLOS Genet — https://doi.org/10.1371/journal.pgen.1011508 (backe2023saccharomycescerevisiaeas pages 12-13)
- Guimarães, 2022, thesis with direct screening application relevant to 2023-2024 work — URL not available in retrieved metadata (guimaraes2022developmentofa pages 63-66, guimaraes2022developmentofa pages 1-8)

Table: This table summarizes the functional annotation of Saccharomyces cerevisiae CDC37 (UniProt P06101), including identity, mechanism, pathways, regulation, localization, quantitative evidence, and recent research or application themes. It is useful as a concise evidence-backed reference for narrative reporting.

References

  1. (farrell2000cdc37promotesthe pages 1-2): Alison Farrell and David O. Morgan. Cdc37 promotes the stability of protein kinases cdc28 and cak1. Molecular and Cellular Biology, 20:749-754, Feb 2000. URL: https://doi.org/10.1128/mcb.20.3.749-754.2000, doi:10.1128/mcb.20.3.749-754.2000. This article has 78 citations and is from a domain leading peer-reviewed journal.

  2. (mandal2007cdc37hasdistinct pages 1-3): Atin K. Mandal, Paul Lee, Jennifer A. Chen, Nadinath Nillegoda, Alana Heller, Susan DiStasio, Handy Oen, Jacob Victor, Devi M. Nair, Jeffrey L. Brodsky, and Avrom J. Caplan. Cdc37 has distinct roles in protein kinase quality control that protect nascent chains from degradation and promote posttranslational maturation. The Journal of Cell Biology, 176:319-328, Jan 2007. URL: https://doi.org/10.1083/jcb.200604106, doi:10.1083/jcb.200604106. This article has 128 citations.

  3. (miyata2004ck2controlsmultiple pages 1-2): Yoshihiko Miyata and Eisuke Nishida. Ck2 controls multiple protein kinases by phosphorylating a kinase-targeting molecular chaperone, cdc37. Molecular and Cellular Biology, 24:4065-4074, May 2004. URL: https://doi.org/10.1128/mcb.24.9.4065-4074.2004, doi:10.1128/mcb.24.9.4065-4074.2004. This article has 184 citations and is from a domain leading peer-reviewed journal.

  4. (millson2014cdc37engagesin pages 1-2): Stefan Millson, Patricija van Oosten-Hawle, Mohammed A. Alkuriji, Andrew Truman, Marco Siderius, and Peter W. Piper. Cdc37 engages in stable, s14a mutation-reinforced association with the most atypical member of the yeast kinome, cdk-activating kinase (cak1). Cell Stress and Chaperones, 19:695-703, Sep 2014. URL: https://doi.org/10.1007/s12192-014-0497-4, doi:10.1007/s12192-014-0497-4. This article has 5 citations and is from a peer-reviewed journal.

  5. (verba2017howhsp90and pages 4-6): Kliment A. Verba and David A. Agard. How hsp90 and cdc37 lubricate kinase molecular switches. Trends in biochemical sciences, 42 10:799-811, Oct 2017. URL: https://doi.org/10.1016/j.tibs.2017.07.002, doi:10.1016/j.tibs.2017.07.002. This article has 120 citations and is from a domain leading peer-reviewed journal.

  6. (verba2017howhsp90and media 39c974c8): Kliment A. Verba and David A. Agard. How hsp90 and cdc37 lubricate kinase molecular switches. Trends in biochemical sciences, 42 10:799-811, Oct 2017. URL: https://doi.org/10.1016/j.tibs.2017.07.002, doi:10.1016/j.tibs.2017.07.002. This article has 120 citations and is from a domain leading peer-reviewed journal.

  7. (verba2017howhsp90and media fe609c0f): Kliment A. Verba and David A. Agard. How hsp90 and cdc37 lubricate kinase molecular switches. Trends in biochemical sciences, 42 10:799-811, Oct 2017. URL: https://doi.org/10.1016/j.tibs.2017.07.002, doi:10.1016/j.tibs.2017.07.002. This article has 120 citations and is from a domain leading peer-reviewed journal.

  8. (guimaraes2022developmentofa pages 20-25): JPR Guimarães. Development of a yeast-based screening assay for inhibitors of the kinase chaperone cdc37. Unknown journal, 2022.

  9. (farrell2000cdc37promotesthe pages 5-6): Alison Farrell and David O. Morgan. Cdc37 promotes the stability of protein kinases cdc28 and cak1. Molecular and Cellular Biology, 20:749-754, Feb 2000. URL: https://doi.org/10.1128/mcb.20.3.749-754.2000, doi:10.1128/mcb.20.3.749-754.2000. This article has 78 citations and is from a domain leading peer-reviewed journal.

  10. (yang2007cdc37pisinvolved pages 1-2): Xiao-Xian Yang, Patricija Hawle, Jan Paul Bebelman, Annemarie Meenhuis, Marco Siderius, and Saskia M. van der Vies. Cdc37p is involved in osmoadaptation and controls high osmolarity-induced cross-talk via the map kinase kss1p. FEMS yeast research, 7 6:796-807, Sep 2007. URL: https://doi.org/10.1111/j.1567-1364.2007.00237.x, doi:10.1111/j.1567-1364.2007.00237.x. This article has 15 citations and is from a peer-reviewed journal.

  11. (backe2023saccharomycescerevisiaeas pages 12-13): Sarah J. Backe, Mehdi Mollapour, and Mark R. Woodford. saccharomyces cerevisiae as a tool for deciphering hsp90 molecular chaperone function. Essays in Biochemistry, 67:781-795, Sep 2023. URL: https://doi.org/10.1042/ebc20220224, doi:10.1042/ebc20220224. This article has 5 citations and is from a peer-reviewed journal.

  12. (guimaraes2022developmentofa pages 1-8): JPR Guimarães. Development of a yeast-based screening assay for inhibitors of the kinase chaperone cdc37. Unknown journal, 2022.

  13. (guimaraes2022developmentofa pages 63-66): JPR Guimarães. Development of a yeast-based screening assay for inhibitors of the kinase chaperone cdc37. Unknown journal, 2022.

  14. (millson2014cdc37engagesin pages 8-9): Stefan Millson, Patricija van Oosten-Hawle, Mohammed A. Alkuriji, Andrew Truman, Marco Siderius, and Peter W. Piper. Cdc37 engages in stable, s14a mutation-reinforced association with the most atypical member of the yeast kinome, cdk-activating kinase (cak1). Cell Stress and Chaperones, 19:695-703, Sep 2014. URL: https://doi.org/10.1007/s12192-014-0497-4, doi:10.1007/s12192-014-0497-4. This article has 5 citations and is from a peer-reviewed journal.

  15. (yang2007cdc37pisinvolved pages 12-12): Xiao-Xian Yang, Patricija Hawle, Jan Paul Bebelman, Annemarie Meenhuis, Marco Siderius, and Saskia M. van der Vies. Cdc37p is involved in osmoadaptation and controls high osmolarity-induced cross-talk via the map kinase kss1p. FEMS yeast research, 7 6:796-807, Sep 2007. URL: https://doi.org/10.1111/j.1567-1364.2007.00237.x, doi:10.1111/j.1567-1364.2007.00237.x. This article has 15 citations and is from a peer-reviewed journal.

  16. (boczek2015thematurationofa pages 20-24): E Boczek. The maturation of src kinase by the molecular chaperone hsp90 and its kinase specific cochaperone cdc37. Unknown journal, 2015.

  17. (boczek2015thematurationof pages 20-24): E Boczek. The maturation of src kinase by the molecular chaperone hsp90 and its kinase specific cochaperone cdc37. Unknown journal, 2015.

  18. (boczek2015thematurationofa pages 15-20): E Boczek. The maturation of src kinase by the molecular chaperone hsp90 and its kinase specific cochaperone cdc37. Unknown journal, 2015.

Citations

  1. backe2023saccharomycescerevisiaeas pages 12-13
  2. guimaraes2022developmentofa pages 20-25
  3. guimaraes2022developmentofa pages 1-8
  4. guimaraes2022developmentofa pages 63-66
  5. boczek2015thematurationofa pages 20-24
  6. boczek2015thematurationof pages 20-24
  7. boczek2015thematurationofa pages 15-20
  8. https://doi.org/10.1042/ebc20220224
  9. https://doi.org/10.1016/j.tibs.2017.07.002
  10. https://doi.org/10.1128/mcb.20.3.749-754.2000
  11. https://doi.org/10.1083/jcb.200604106
  12. https://doi.org/10.1007/s12192-014-0497-4
  13. https://doi.org/10.1111/j.1567-1364.2007.00237.x
  14. https://doi.org/10.1128/mcb.24.9.4065-4074.2004
  15. https://doi.org/10.1016/j.molcel.2008.07.021
  16. https://doi.org/10.1371/journal.pgen.1011508
  17. https://doi.org/10.1128/mcb.20.3.749-754.2000,
  18. https://doi.org/10.1083/jcb.200604106,
  19. https://doi.org/10.1128/mcb.24.9.4065-4074.2004,
  20. https://doi.org/10.1007/s12192-014-0497-4,
  21. https://doi.org/10.1016/j.tibs.2017.07.002,
  22. https://doi.org/10.1111/j.1567-1364.2007.00237.x,
  23. https://doi.org/10.1042/ebc20220224,

📚 Additional Documentation

Bioreason Rl Predictions

(CDC37-bioreason-rl-predictions.md)

BioReason Chat Export

Exported on March 22, 2026 at 02:07 AM


Organism: Saccharomyces cerevisiae

Sequence:

MAIDYSKWDKIELSDDSDVEVHPNVDKKSFIKWKQQSIHEQRFKRNQDIKNLETQVDMYSHLNKRVDRILSNLPESSLTDLPAVTKFLNANFDKMEKSKGENVDPEIATYNEMVEDLFEQLAKDLDKEGKDSKSPSLIRDAILKHRAKIDSVTVEAKKKLDELYKEKNAHISSEDIHTGFDSSFMNKQKGGAKPLEATPSEALSSAAESNILNKLAKSSVPQTFIDFKDDPMKLAKETEEFGKISINEYSKSQKFLLEHLPIISEQQKDALMMKAFEYQLHGDDKMTLQVIHQSELMAYIKEIYDMKKIPYLNPMELSNVINMFFEKVIFNKDKPMGKESFLRSVQEKFLHIQKRSKILQQEEMDESNAEGVETIQLKSLDDSTELEVNLPDFNSKDPEEMKKVKVFKTLIPEKMQEAIMTKNLDNINKVFEDIPIEEAEKLLEVFNDIDIIGIKAILENEKDFQSLKDQYEQDHEDATMENLSLNDRDGGGDNHEEVKHTADTVD

Thinking Trace

I begin by dissecting the InterPro architecture. The polypeptide is assigned to IPR004918 (Cdc37 family, residues 1–474), establishing a dedicated co-chaperone scaffold. Its N-terminus is organized by IPR013855 (Cdc37, N-terminal domain, residues 2–183), a module typically used to engage client proteins—particularly unstable kinases. The central region carries IPR013874 (Cdc37, Hsp90 binding, residues 186–371), reinforced by IPR038189 (Cdc37, Hsp90-binding domain superfamily, residues 232–365). This central core causally defines the protein’s role: it binds and positions Hsp90 to form a productive chaperone assembly. The C-terminus is structured by IPR013873 (Cdc37, C-terminal domain, residues 388–491), a region that commonly stabilizes the co-chaperone fold and mediates additional client or cofactor contacts. The ordered layout—N-terminal client-capture domain, central Hsp90-binding engine, and C-terminal stabilizer—creates a tri-partite machine that recruits specific substrates and couples them to Hsp90-dependent folding cycles.

From this architecture, the molecular function resolves as selective protein binding. The N-terminal domain confers affinity for labile client proteins, while the central module binds Hsp90; together they enforce high-avidity interactions characteristic of co-chaperone assemblies. This supports protein binding (GO:0005515) as the operative molecular function, with binding specificity arising from coordinated recognition of both chaperone and client.

The biological process follows directly: by tethering kinase-like clients to an Hsp90-centered machine, this co-chaperone drives chaperone-mediated folding and maturation of metastable proteins. This mechanism underlies protein folding (GO:0006457), ensuring that clients attain and maintain their active conformations required for signaling and cell-cycle control.

Cellular placement is inferred from function and modularity. Such chaperone-cofactor systems operate where nascent and stress-labile proteins accumulate and where signaling hubs reside—predominantly the cytosol. The absence of transmembrane features and the soluble, multi-interface architecture point to a cytosolic environment, aligning with cytosol (GO:0005829) as the most parsimonious cellular component.

Mechanistically, the protein acts as a targeting and stabilizing hub: the N-terminal domain captures kinase-class clients; the central Hsp90-binding region docks Hsp90 and aligns ATP-driven conformational cycles; and the C-terminal domain consolidates the assembly for efficient folding. This suggests transient assemblies with Hsp90 and the Hsp70 system, and preferential handoff to kinase clients. I therefore hypothesize interactions with the core Hsp90/Hsp70 machinery and kinase substrates, forming a dynamic chaperone module that stabilizes and matures metastable signaling proteins in the cytosol.

Functional Summary

A soluble co-chaperone that assembles with the Hsp90 system to stabilize and mature metastable client proteins—especially kinase-class substrates—in baker’s yeast. Its N-terminal module captures labile clients, a central region docks Hsp90 to drive ATP-dependent folding cycles, and the C-terminal domain consolidates the assembly. By orchestrating chaperone-mediated folding in the cytosol, it promotes the attainment and maintenance of functional conformations central to cellular signaling and proteostasis.

UniProt Summary

Co-chaperone that binds to the molecular chaperone Hsp90 and promotes the maturation of specific Hsp90 client proteins.

InterPro Domains

  • Cdc37 (IPR004918, family) — residues 1-474
  • Cdc37, N-terminal domain (IPR013855, domain) — residues 2-183
  • Cdc37, Hsp90 binding (IPR013874, domain) — residues 186-371
  • Cdc37, Hsp90-binding domain superfamily (IPR038189, homologous_superfamily) — residues 232-365
  • Cdc37, C-terminal (IPR013873, domain) — residues 388-491

GO Terms

Molecular Function: molecular_function (GO:0003674), binding (GO:0005488), protein binding (GO:0005515), unfolded protein binding (GO:0051082)

Biological Process: biological_process (GO:0008150), biological regulation (GO:0065007), positive regulation of biological process (GO:0048518), response to stimulus (GO:0050896), regulation of biological process (GO:0050789), cellular process (GO:0009987), signaling (GO:0023052), response to abiotic stimulus (GO:0009628), regulation of biological quality (GO:0065008), positive regulation of signaling (GO:0023056), response to chemical (GO:0042221), positive regulation of response to stimulus (GO:0048584), cell cycle process (GO:0022402), regulation of cellular process (GO:0050794), cell cycle (GO:0007049), regulation of response to stimulus (GO:0048583), cellular response to stimulus (GO:0051716), cellular component organization or biogenesis (GO:0071840), regulation of signaling (GO:0023051), response to stress (GO:0006950), microtubule-based process (GO:0007017), cell communication (GO:0007154), signal transduction (GO:0007165), positive regulation of cellular process (GO:0048522), regulation of cell cycle (GO:0051726), positive regulation of signal transduction (GO:0009967), cellular response to environmental stimulus (GO:0104004), cellular component biogenesis (GO:0044085), intracellular signal transduction (GO:0035556), spindle pole body organization (GO:0051300), regulation of cell communication (GO:0010646), cellular response to chemical stimulus (GO:0070887), cellular response to stress (GO:0033554), cellular response to abiotic stimulus (GO:0071214), regulation of signal transduction (GO:0009966), response to osmotic stress (GO:0006970), cellular component organization (GO:0016043), positive regulation of cell communication (GO:0010647), microtubule cytoskeleton organization (GO:0000226), microtubule organizing center organization (GO:0031023), regulation of protein stability (GO:0031647), cellular response to chemical stress (GO:0062197), cellular response to osmotic stress (GO:0071470), MAPK cascade (GO:0000165), osmosensory signaling pathway (GO:0007231), positive regulation of intracellular signal transduction (GO:1902533), protein stabilization (GO:0050821), organelle organization (GO:0006996), regulation of intracellular signal transduction (GO:1902531), stress-activated protein kinase signaling cascade (GO:0031098), cellular component assembly (GO:0022607), cytoskeleton organization (GO:0007010), regulation of MAPK cascade (GO:0043408), stress-activated MAPK cascade (GO:0051403), positive regulation of MAPK cascade (GO:0043410)

Cellular Component: cellular_component (GO:0005575), cellular anatomical entity (GO:0110165), cytoplasm (GO:0005737), intracellular anatomical structure (GO:0005622)


Generated by BioReason

Bioreason Rl Review

(CDC37-bioreason-rl-review.md)

BioReason-Pro RL Review: CDC37 (S. cerevisiae)

Source: CDC37-bioreason-rl-predictions.md

  • Correctness: 4/5
  • Completeness: 3/5

Functional Summary Review

The BioReason summary states:

A soluble co-chaperone that assembles with the Hsp90 system to stabilize and mature metastable client proteins -- especially kinase-class substrates -- in baker's yeast.

This is accurate. The curated review confirms CDC37 is an Hsp90 co-chaperone that promotes maturation of specific Hsp90 client proteins, with kinase specificity well documented (GO:0019901 protein kinase binding from GO_REF:0000002; protein stabilization GO:0050821).

Its N-terminal module captures labile clients, a central region docks Hsp90 to drive ATP-dependent folding cycles, and the C-terminal domain consolidates the assembly.

This domain-level description correctly maps to the three known CDC37 domains (IPR013855, IPR013874, IPR013873) and their functional roles.

By orchestrating chaperone-mediated folding in the cytosol, it promotes the attainment and maintenance of functional conformations central to cellular signaling and proteostasis.

Cytosolic localization is correct (multiple lines of evidence in curated review: IBA, IEA, HDA). The connection to protein folding (GO:0006457) and protein stabilization (GO:0050821) is accurate.

The summary correctly captures protein folding and protein stabilization as core functions. However, it misses several important non-core but documented functions: the requirement for passage through START in the cell cycle (GO:0051726), involvement in HOG and PKC MAP kinase signaling cascades (GO:0043410, GO:0038066), spindle pole body duplication (GO:0030474), and the cellular hyperosmotic response (GO:0071474). These are context-dependent functions documented by IMP evidence (PMID:17220467, PMID:9060463, PMID:7753858).

The molecular function is described as "selective protein binding," which the curated review marks as over-annotated when generic (GO:0005515). The more informative terms are heat shock protein binding (GO:0031072), protein-folding chaperone binding (GO:0051087), and protein kinase binding (GO:0019901).

Comparison with interpro2go:

The interpro2go annotation (GO_REF:0000002) provides protein kinase binding (GO:0019901), which is a specific and informative molecular function term. BioReason's summary describes kinase-client binding in prose but does not reach this level of specificity in its GO term predictions -- it outputs only protein binding (GO:0005515) and unfolded protein binding (GO:0051082) as MF terms, both of which the curated review marks as over-annotated. BioReason adds narrative value about the tri-partite domain architecture and mechanism but does not improve on interpro2go for functional specificity.

Notes on thinking trace

The trace correctly identifies the three-domain architecture and its functional implications. The reasoning from domain structure to co-chaperone function is sound. The prediction of Hsp70 system cooperation is reasonable but the specific downstream signaling roles (MAPK cascades, cell cycle) are entirely absent from the reasoning, which stays at the level of generic chaperone biology.

📄 View Raw YAML

id: P06101
gene_symbol: CDC37
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:559292
  label: Saccharomyces cerevisiae
description: >-
  CDC37 encodes an essential cytosolic Hsp90 co-chaperone that specializes the
  Hsp90 system for protein kinase clients. Cdc37 binds protein kinases and Hsp90,
  promotes Hsp90-kinase complex formation, protects nascent kinase chains from
  rapid degradation, and supports post-translational kinase maturation. Its
  client effects explain downstream roles in Cdc28/Cak1-dependent cell-cycle
  progression, MAP kinase signaling, osmotic and cell wall stress responses, and
  spindle pole body duplication, but the core function is kinase-specific
  chaperone/adaptor activity rather than those downstream pathways themselves.
existing_annotations:
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      The phylogenetic cytoplasm annotation is consistent with experimental
      localization and with Cdc37 acting in cytosolic Hsp90-kinase complexes.
    action: ACCEPT
    reason: >-
      Cdc37 is experimentally detected in the cytoplasm and its core Hsp90
      co-chaperone activity is carried out in the cytosolic chaperone machinery.
    supported_by:
    - reference_id: PMID:14562095
      supporting_text: Global analysis of protein localization in budding yeast.
    - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
      supporting_text: >-
        Cdc37's functional locale is best described as the cytosolic chaperone
        machinery, where it forms transient Cdc37-kinase and
        Hsp90-Cdc37-kinase complexes.
- term:
    id: GO:0006457
    label: protein folding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      Cdc37 is a kinase-directed Hsp90 co-chaperone required for productive
      folding and maturation of protein kinases.
    action: ACCEPT
    reason: >-
      Although Cdc37 is not a general foldase for all proteins, the annotation
      accurately captures its core role in protein kinase folding/maturation in
      the Hsp90 pathway.
    supported_by:
    - reference_id: PMID:17242065
      supporting_text: >-
        Cdc37 functions at distinct steps in kinase biogenesis that involves
        protecting nascent chains from rapid degradation followed by its folding
        function in association with Hsp90.
    - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
      supporting_text: >-
        Cdc37 selectively recognizes kinase clients and promotes their
        stabilization and productive engagement with Hsp90 to achieve
        folding/maturation and functional activation.
- term:
    id: GO:0031072
    label: heat shock protein binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      The annotation reflects the well-established physical and functional
      interaction between Cdc37 and Hsp90.
    action: ACCEPT
    reason: >-
      Hsp90 binding is central to Cdc37 function as a kinase-targeting adaptor
      and is supported by biochemical and genetic evidence for Hsp90-Cdc37-kinase
      complexes.
    supported_by:
    - reference_id: PMID:9242486
      supporting_text: >-
        The identification of Cdc37 as the 50-kD protein in several Hsp90-kinase
        complexes, together with other data, led to the recent suggestion that
        Cdc37 is a kinase-targeting "subunit" of Hsp90.
    - reference_id: PMID:17220467
      supporting_text: >-
        The interaction of Hsp90, Slt2p, and Hog1p with Cdc37p depends on the
        phosphorylation status of Cdc37p.
- term:
    id: GO:0050821
    label: protein stabilization
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      Protein stabilization is a core biological process for Cdc37, specifically
      stabilization of protein kinase clients.
    action: ACCEPT
    reason: >-
      Multiple studies show that Cdc37 maintains kinase abundance and protects
      newly synthesized kinases from degradation.
    supported_by:
    - reference_id: PMID:17242065
      supporting_text: >-
        showed that 51 had decreased abundance compared with levels in the
        wild-type strain.
    - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
      supporting_text: >-
        In a panel of 65 kinases, 51 showed decreased abundance in a cdc37
        mutant, supporting a broad role in kinase homeostasis.
- term:
    id: GO:0051082
    label: unfolded protein binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      Cdc37 does bind non-native kinase clients, but the broad "unfolded protein
      binding" term obscures the kinase-specific co-chaperone mechanism.
    action: MODIFY
    reason: >-
      Replace the generic binding term with protein-folding chaperone activity;
      kinase client binding is already captured by the accepted GO:0019901 annotation.
    proposed_replacement_terms:
    - id: GO:0044183
      label: protein folding chaperone
    supported_by:
    - reference_id: PMID:17242065
      supporting_text: >-
        Cdc37 protects nascent kinase chains from rapid degradation shortly
        after synthesis.
- term:
    id: GO:0051087
    label: protein-folding chaperone binding
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  review:
    summary: >-
      This term captures Cdc37 binding to the Hsp90 chaperone machinery.
    action: ACCEPT
    reason: >-
      Protein-folding chaperone binding is a core molecular interaction for
      Cdc37, which couples kinase clients to Hsp90.
    supported_by:
    - reference_id: PMID:9242486
      supporting_text: >-
        the very similar chaperone activities of the two proteins, uncovered
        through in vitro analysis, diverge in vivo in specific signal
        transduction pathways.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  review:
    summary: >-
      UniProtKB subcellular-location mapping to cytoplasm is correct.
    action: ACCEPT
    reason: >-
      The automated cytoplasm annotation agrees with the experimental
      localization and the cytosolic Hsp90 co-chaperone function.
    supported_by:
    - reference_id: UniProt:P06101
      supporting_text: 'SUBCELLULAR LOCATION: Cytoplasm.'
- term:
    id: GO:0019901
    label: protein kinase binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  review:
    summary: >-
      InterPro-derived protein kinase binding is highly specific and captures
      the key client-recognition activity of Cdc37.
    action: ACCEPT
    reason: >-
      Cdc37 is a kinase-targeting co-chaperone, and protein kinase binding is
      the most informative currently annotated molecular function for its client
      specificity.
    supported_by:
    - reference_id: UniProt:P06101
      supporting_text: >-
        Co-chaperone that binds to numerous kinases and promotes their
        interaction with the Hsp90 complex, resulting in their stabilization.
    - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
      supporting_text: >-
        Cdc37 selectively recognizes kinase clients and promotes their
        stabilization and productive engagement with Hsp90.
- term:
    id: GO:0051301
    label: cell division
  evidence_type: IEA
  original_reference_id: GO_REF:0000043
  review:
    summary: >-
      Cell division is a true consequence of Cdc37 activity through Cdc28/Cak1
      and spindle-pole-body kinase clients, but it is not the molecular core
      function of Cdc37.
    action: KEEP_AS_NON_CORE
    reason: >-
      Retain as a supported downstream biological process while keeping the core
      function focused on kinase-specific chaperoning and stabilization.
    supported_by:
    - reference_id: PMID:7753858
      supporting_text: Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.
    - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
      supporting_text: >-
        CDC37 is essential for G1/Start progression and for activation of the
        major cyclin-dependent kinase Cdc28.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:15766533
  review:
    summary: >-
      This high-throughput interaction annotation is real evidence of physical
      interactions but the term is too generic for Cdc37.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Protein binding does not distinguish Cdc37's specific Hsp90/kinase
      co-chaperone role; specific kinase and chaperone binding annotations are
      more informative.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:15879519
  review:
    summary: >-
      The interaction evidence supports Hsp90 pathway biology but the generic
      protein binding term is uninformative.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Use specific Hsp90/chaperone and kinase-client terms rather than generic
      protein binding for Cdc37.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:16554755
  review:
    summary: >-
      Large-scale complex data document interactions but do not by themselves
      define a specific molecular function.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Generic protein binding is over-annotated for a co-chaperone whose
      specific binding modes are captured by protein kinase binding and
      protein-folding chaperone binding.
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:19536198
  review:
    summary: >-
      The chaperone-protein interaction atlas supports Cdc37 involvement in the
      chaperone network, but the GO term is too broad.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      The annotation should not be treated as core because more specific
      chaperone and kinase-client binding terms describe the function.
- term:
    id: GO:0005737
    label: cytoplasm
  evidence_type: HDA
  original_reference_id: PMID:14562095
  review:
    summary: >-
      High-throughput localization to cytoplasm agrees with the known site of
      Cdc37-Hsp90 kinase-chaperone action.
    action: ACCEPT
    reason: >-
      Cytoplasm is a supported core cellular component for Cdc37.
- term:
    id: GO:0043410
    label: positive regulation of MAPK cascade
  evidence_type: IMP
  original_reference_id: PMID:17220467
  review:
    summary: >-
      Cdc37 positively affects HOG and PKC MAPK pathway output by stabilizing
      and interacting with Hog1 and Slt2.
    action: KEEP_AS_NON_CORE
    reason: >-
      This is well-supported pathway-level biology but is downstream of the
      core kinase-chaperone function.
    supported_by:
    - reference_id: PMID:17220467
      supporting_text: >-
        levels of the MAPKs Hog1p and Slt2p (Mpk1p) in cells are reduced in a
        cdc37-S14A mutant
- term:
    id: GO:0071474
    label: cellular hyperosmotic response
  evidence_type: IMP
  original_reference_id: PMID:17220467
  review:
    summary: >-
      The hyperosmotic-response phenotype is supported by cdc37-S14A effects on
      Hog1/Hsp90/Cdc37 interactions.
    action: KEEP_AS_NON_CORE
    reason: >-
      Retain as a valid stress-response annotation, but do not elevate it above
      the kinase-specific chaperone role.
    supported_by:
    - reference_id: PMID:17220467
      supporting_text: >-
        Mutation of the phosphorylation site Ser14 in Cdc37p renders cells
        sensitive to osmotic stress.
- term:
    id: GO:0071852
    label: fungal-type cell wall organization or biogenesis
  evidence_type: IMP
  original_reference_id: PMID:17220467
  review:
    summary: >-
      Cdc37 affects cell wall stress responses through the Slt2/PKC MAPK pathway.
    action: KEEP_AS_NON_CORE
    reason: >-
      This is a supported downstream pathway consequence of kinase chaperoning,
      not the core molecular role.
    supported_by:
    - reference_id: PMID:17220467
      supporting_text: >-
        during cell wall stress, the interaction of Slt2p with Cdc37p and Hsp90
        is crucial for Slt2p-dependent downstream responses
- term:
    id: GO:0038066
    label: p38MAPK cascade
  evidence_type: IPI
  original_reference_id: PMID:17220467
  review:
    summary: >-
      In yeast this annotation reflects Hog1 MAPK interaction and pathway
      support by Cdc37.
    action: KEEP_AS_NON_CORE
    reason: >-
      The physical interaction is relevant but represents a client/pathway
      context rather than the core function of Cdc37.
    supported_by:
    - reference_id: PMID:17220467
      supporting_text: >-
        Hog1p and Slt2p both interact in a complex with Cdc37p in vivo.
- term:
    id: GO:0071474
    label: cellular hyperosmotic response
  evidence_type: IPI
  original_reference_id: PMID:17220467
  review:
    summary: >-
      Interaction with Hog1 supports Cdc37 participation in osmotic stress
      signaling.
    action: KEEP_AS_NON_CORE
    reason: >-
      The annotation is valid as pathway context but should remain non-core
      relative to the kinase-chaperone activity.
    supported_by:
    - reference_id: PMID:17220467
      supporting_text: >-
        the osmosensitive phenotype of the cdc37-S14A mutant is due to the loss
        of the interaction between Cdc37p, Hog1p, and Hsp90.
- term:
    id: GO:0030474
    label: spindle pole body duplication
  evidence_type: IMP
  original_reference_id: PMID:9060463
  review:
    summary: >-
      Cdc37 is required for proper spindle pole body duplication, likely through
      kinase-client biology involving Mps1.
    action: KEEP_AS_NON_CORE
    reason: >-
      Retain as a supported cell-cycle phenotype, but classify as non-core
      because it is downstream of Cdc37's kinase-chaperone role.
    supported_by:
    - reference_id: PMID:9060463
      supporting_text: The yeast CDC37 gene interacts with MPS1 and is required for proper execution of spindle pole body duplication.
- term:
    id: GO:0050821
    label: protein stabilization
  evidence_type: IMP
  original_reference_id: PMID:17242065
  review:
    summary: >-
      This annotation directly captures the experimentally demonstrated role of
      Cdc37 in kinase abundance and nascent-chain quality control.
    action: ACCEPT
    reason: >-
      Protein stabilization of kinase clients is central to Cdc37 function.
    supported_by:
    - reference_id: PMID:17242065
      supporting_text: >-
        Results from our pulse-labeling studies showed that Cdc37 protects
        nascent kinase chains from rapid degradation shortly after synthesis.
- term:
    id: GO:0051082
    label: unfolded protein binding
  evidence_type: IDA
  original_reference_id: PMID:9242486
  review:
    summary: >-
      The experiment supports molecular chaperone activity, but the GO term is
      too generic for Cdc37's kinase-directed function.
    action: MODIFY
    reason: >-
      Replace generic unfolded protein binding with protein folding chaperone,
      while leaving protein kinase binding to the existing accepted GO:0019901 annotation.
    proposed_replacement_terms:
    - id: GO:0044183
      label: protein folding chaperone
    supported_by:
    - reference_id: PMID:9242486
      supporting_text: >-
        In vitro, Cdc37 maintains denatured beta-galactosidase in an
        activation-competent state without reactivating it and stabilizes
        mature, but unstable, casein kinase II.
- term:
    id: GO:0051726
    label: regulation of cell cycle
  evidence_type: IMP
  original_reference_id: PMID:7753858
  review:
    summary: >-
      Cdc37 regulates cell-cycle progression through effects on the cyclin-
      dependent kinase Cdc28.
    action: KEEP_AS_NON_CORE
    reason: >-
      Cell-cycle regulation is an important downstream consequence of kinase
      chaperoning but should not be treated as the primary molecular function.
    supported_by:
    - reference_id: PMID:7753858
      supporting_text: Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000043
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: PMID:14562095
  title: Global analysis of protein localization in budding yeast.
  findings: []
- id: PMID:15766533
  title: 'Navigating the chaperone network: an integrative map of physical and genetic interactions mediated by the hsp90 chaperone.'
  findings: []
- id: PMID:15879519
  title: 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).
  findings: []
- id: PMID:16554755
  title: Global landscape of protein complexes in the yeast Saccharomyces cerevisiae.
  findings: []
- id: PMID:17220467
  title: Cdc37p is required for stress-induced high-osmolarity glycerol and protein kinase C mitogen-activated protein kinase pathway functionality by interaction with Hog1p and Slt2p (Mpk1p).
  findings:
  - statement: Cdc37 supports HOG and PKC MAPK signaling by stabilizing/interacting with Hog1 and Slt2.
    supporting_text: >-
      Levels of the MAPKs Hog1p and Slt2p in cells are reduced in a
      cdc37-S14A mutant, and downstream responses mediated by Hog1p and Slt2p
      are compromised.
- id: PMID:17242065
  title: Cdc37 has distinct roles in protein kinase quality control that protect nascent chains from degradation and promote posttranslational maturation.
  findings:
  - statement: Cdc37 broadly stabilizes the yeast kinome.
    supporting_text: >-
      Analysis of 65 Saccharomyces cerevisiae protein kinases showed that 51 had
      decreased abundance compared with levels in the wild-type strain.
  - statement: Cdc37 protects nascent kinase chains from rapid degradation.
    supporting_text: >-
      Results from pulse-labeling studies showed that Cdc37 protects nascent
      kinase chains from rapid degradation shortly after synthesis.
- id: PMID:19536198
  title: 'An atlas of chaperone-protein interactions in Saccharomyces cerevisiae: implications to protein folding pathways in the cell.'
  findings: []
- id: PMID:7753858
  title: Cdc37 is required for association of the protein kinase Cdc28 with G1 and mitotic cyclins.
  findings: []
- id: PMID:9060463
  title: The yeast CDC37 gene interacts with MPS1 and is required for proper execution of spindle pole body duplication.
  findings: []
- id: PMID:9242486
  title: Cdc37 is a molecular chaperone with specific functions in signal transduction.
  findings:
  - statement: Cdc37 has intrinsic chaperone activity and stabilizes kinase clients.
    supporting_text: >-
      In vitro, Cdc37 maintains denatured beta-galactosidase in an
      activation-competent state without reactivating it and stabilizes mature,
      but unstable, casein kinase II.
- id: UniProt:P06101
  title: UniProt entry for CDC37/Hsp90 co-chaperone Cdc37
  findings:
  - statement: UniProt summarizes Cdc37 as a kinase-binding Hsp90 co-chaperone.
    supporting_text: >-
      Co-chaperone that binds to numerous kinases and promotes their interaction
      with the Hsp90 complex, resulting in their stabilization.
- id: file:yeast/CDC37/CDC37-deep-research-falcon.md
  title: Falcon deep research report for CDC37
  findings:
  - statement: Falcon synthesis supports kinase-specific Hsp90 co-chaperone function as the core role.
    supporting_text: >-
      CDC37 encodes an essential cytosolic Hsp90 co-chaperone that acts as a
      kinase-targeting adaptor.
- id: file:interpro/panther/PTHR12800/PTHR12800-metadata.yaml
  title: PANTHER family PTHR12800 CDC37-related metadata
  findings:
  - statement: PTHR12800 places yeast Cdc37 in the conserved CDC37-related family.
    supporting_text: PANTHER family PTHR12800 is named CDC37-RELATED and includes the HSP90 co-chaperone CDC37 subfamily.
core_functions:
- molecular_function:
    id: GO:0019901
    label: protein kinase binding
  directly_involved_in:
  - id: GO:0006457
    label: protein folding
  - id: GO:0050821
    label: protein stabilization
  locations:
  - id: GO:0005737
    label: cytoplasm
  description: >-
    Cdc37 is the kinase-targeting adaptor of the cytosolic Hsp90 chaperone
    system. It binds nascent or unstable protein kinase clients, protects many
    kinases from rapid degradation, and promotes subsequent Hsp90-dependent
    maturation. This client-specific chaperone role explains broad effects on
    Cdc28/Cak1 cell-cycle control, MAPK signaling, and spindle-pole-body
    duplication without making those downstream pathways the core function.
  supported_by:
  - reference_id: PMID:17242065
    supporting_text: >-
      showed that 51 had decreased abundance compared with levels in the
      wild-type strain.
  - reference_id: PMID:17242065
    supporting_text: >-
      Cdc37 functions at distinct steps in kinase biogenesis that involves
      protecting nascent chains from rapid degradation followed by its folding
      function in association with Hsp90.
  - reference_id: file:yeast/CDC37/CDC37-deep-research-falcon.md
    supporting_text: >-
      Cdc37 selectively recognizes kinase clients and promotes their
      stabilization and productive engagement with Hsp90 to achieve
      folding/maturation and functional activation.
  - reference_id: file:interpro/panther/PTHR12800/PTHR12800-metadata.yaml
    supporting_text: PANTHER family PTHR12800 is named CDC37-RELATED and includes the HSP90 co-chaperone CDC37 subfamily.
- molecular_function:
    id: GO:0044183
    label: protein folding chaperone
  directly_involved_in:
  - id: GO:0006457
    label: protein folding
  - id: GO:0050821
    label: protein stabilization
  locations:
  - id: GO:0005737
    label: cytoplasm
  description: >-
    Cdc37 has a kinase-directed chaperone/stabilizing activity: it protects
    nascent or unstable kinase clients and keeps them competent for subsequent
    Hsp90-dependent maturation. This captures the GO:0044183 replacement used for
    broad unfolded-protein-binding annotations without treating Cdc37 as a generic
    bulk-folding chaperone.
  supported_by:
  - reference_id: PMID:17242065
    supporting_text: >-
      Cdc37 protects nascent kinase chains from rapid degradation shortly after
      synthesis.
  - reference_id: PMID:9242486
    supporting_text: >-
      In vitro, Cdc37 maintains denatured beta-galactosidase in an
      activation-competent state without reactivating it and stabilizes mature,
      but unstable, casein kinase II.
- molecular_function:
    id: GO:0051087
    label: protein-folding chaperone binding
  directly_involved_in:
  - id: GO:0006457
    label: protein folding
  locations:
  - id: GO:0005737
    label: cytoplasm
  description: >-
    Cdc37 binds the Hsp90 protein-folding chaperone system and helps load kinase
    clients into Hsp90-containing maturation complexes. This Hsp90-binding
    adaptor role is an inseparable part of the core kinase co-chaperone
    mechanism.
  supported_by:
  - reference_id: PMID:9242486
    supporting_text: >-
      The identification of Cdc37 as the 50-kD protein in several Hsp90-kinase
      complexes, together with other data, led to the recent suggestion that
      Cdc37 is a kinase-targeting "subunit" of Hsp90.
  - reference_id: PMID:17220467
    supporting_text: >-
      Hog1p and Slt2p both interact in a complex with Cdc37p in vivo.
proposed_new_terms: []
suggested_questions:
- question: >-
    Which yeast kinase clients require Cdc37 primarily for nascent-chain
    stabilization versus later Hsp90-dependent maturation?
- question: >-
    Are there yeast stress conditions that shift Cdc37 client specificity beyond
    the kinases already surveyed by abundance and interaction assays?
suggested_experiments:
- experiment_type: quantitative proteomics
  hypothesis: >-
    Distinct kinase subclasses show different dependence on Cdc37 for
    nascent-chain stabilization versus post-translational maturation.
  description: >-
    Pulse-SILAC or equivalent time-resolved proteomics in phosphosite and
    temperature-sensitive cdc37 mutants, paired with kinase activity assays, to
    separate defects in kinase synthesis, stability, and maturation.