Hsp90-Dependent Activation of Protein Kinases Is Regulated by Chaperone-Targeted Dephosphorylation of Cdc37

Vaughan, Cara K.; Mollapour, Mehdi; Smith, Jennifer; Truman, Andrew W.; Hu, Bin; Good, Valerie M.; Panaretou, Barry; Neckers, Len; Clarke, Paul A.; Workman, Paul; Piper, Peter W.; Prodromou, Chrisostomos; Pearl, Laurence H.

doi:10.1016/j.molcel.2008.07.021

Cited by 185 publications

(187 citation statements)

References 46 publications

Supporting

Mentioning

178

Contrasting

Unclassified

Order By: Relevance

“…These mutations also impair PP5's ability to dephosphorylate phospho-GR-Ser211, another known target of PP5 discussed in detail later (2). These data are in agreement with our previous work, in which overexpression of PP5 in HCT116 colon cancer cells enhanced Cdc37 dephosphorylation (8).…”

Section: -23)supporting

confidence: 92%

“…Dysregulation of this step by overexpression of PP5 with concomitant reduction in phospho-Cdc37-Ser13 results in reduced Raf-1 activity in HCT116 cells. In yeast, both the overexpression and deletion of the ortholog, Ppt1, causes reduced v-Src activity (8). To understand how Cdc37 dephosphorylation affects the activation mechanism of Hsp90-dependent kinases, we investigated the impact of PP5 mutants on chaperoning of the kinase clients Cdk4 and Raf-1.…”

Section: -23)mentioning

confidence: 99%

“…Many established PP5 substrates are dependent on Hsp90 for their activation (known as Hsp90 clients). In addition to a requirement for Hsp90's chaperone activity, it is likely that these PP5 substrates require Hsp90 to act as a molecular bridge to bring the catalytic domain of PP5 in close proximity to enable dephosphorylation, which has been shown for the Hsp90 cochaperone Cdc37 (8). In such cases, Hsp90 performs a role similar to that observed by the regulatory subunits of the PP1 and PP2A family (3).…”

mentioning

confidence: 96%

“…Many of these kinases are oncogenes; therefore, the molecular details of their activation are of considerable interest in cancer therapy. Activation is dependent on a cycle of Cdc37-Ser13 phosphorylation by the constitutively active kinase CK2 (11,12) and dephosphorylation by PP5 (8). The mechanisms by which Cdc37 phosphorylation and dephosphorylation regulate kinase activation are not understood.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Structural and functional basis of protein phosphatase 5 substrate specificity

Oberoi

Dunn

Woodford

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

The serine/threonine phosphatase protein phosphatase 5 (PP5) regulates hormone-and stress-induced cellular signaling by association with the molecular chaperone heat shock protein 90 (Hsp90). PP5-mediated dephosphorylation of the cochaperone Cdc37 is essential for activation of Hsp90-dependent kinases. However, the details of this mechanism remain unknown. We determined the crystal structure of a Cdc37 phosphomimetic peptide bound to the catalytic domain of PP5. The structure reveals PP5 utilization of conserved elements of phosphoprotein phosphatase (PPP) structure to bind substrate and provides a template for many PPP-substrate interactions. Our data show that, despite a highly conserved structure, elements of substrate specificity are determined within the phosphatase catalytic domain itself. Structure-based mutations in vivo reveal that PP5-mediated dephosphorylation is required for kinase and steroid hormone receptor release from the chaperone complex. Finally, our data show that hyper-or hypoactivity of PP5 mutants increases Hsp90 binding to its inhibitor, suggesting a mechanism to enhance the efficacy of Hsp90 inhibitors by regulation of PP5 activity in tumors.Hsp90 | PP5 | Cdc37 | chaperone | phosphatase P rotein phosphatase 5 (PP5) has pleiotropic roles in cellular signaling, including DNA damage repair, proliferation of breast cancer cells, circadian cycling, response to cytotoxic stresses, Rac-dependent potassium ion channel activity, and activation of steroid hormone receptors [e.g., glucocorticoid receptor (GR) and estrogen receptor] (1, 2). It is a member of the phosphoprotein phosphatase (PPP) family of serine/threonine phosphatases, which has members that share a highly conserved catalytic core and catalytic mechanism dependent on two metal ions, commonly Mn 2+ . Most PPP family members exhibit high, nonspecific phosphatase activity. Specificity is provided by a large cohort of regulatory and other interacting proteins that function to inhibit basal activity and recruit substrates, thereby finely tuning the enzymes (3). This combinatorial approach enables a small number of catalytic subunits to have the breadth of specificity equivalent to that seen in kinases, which are greater in number by an order of magnitude. Structures of complexes between regulatory and catalytic domains have illuminated the importance of regulatory subunits in facilitating substrate recruitment (3). However, to date, there is no structural information describing how a substrate binds at the active site of a PPP; therefore, a central question remains of how local interactions between the substrate and the catalytic domain contribute to the molecular basis of dephosphorylation.PP5 is unique among the PPP family because it has a low basal activity caused by an autoinhibitory N-terminal tetratricopeptide (TPR) domain (4). Its activity is promoted by a number of cellular factors, including fatty acids and the molecular chaperone heat shock protein 90 (Hsp90) (5), both of which release autoinhibition by interacting with the TPR...

show abstract

Section: -23)supporting

confidence: 92%

Section: -23)mentioning

confidence: 99%

mentioning

confidence: 96%

mentioning

confidence: 99%

See 2 more Smart Citations

Structural and functional basis of protein phosphatase 5 substrate specificity

Oberoi

Dunn

Woodford

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…1D). However, in vivo experiments had suggested that phosphorylation of Cdc37 is involved in regulating its function (19,36). When we used a Cdc37 variant in which the phosphorylation was mimicked by a glutamate substitution (Cdc37 E ), also this variant alone had no significant influence on v-Src (Fig.…”

Section: Significancementioning

confidence: 97%

Conformational processing of oncogenic v-Src kinase by the molecular chaperone Hsp90

Boczek

Reefschläger

Dehling

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Hsp90 is a molecular chaperone involved in the activation of numerous client proteins, including many kinases. The most stringent kinase client is the oncogenic kinase v-Src. To elucidate how Hsp90 chaperones kinases, we reconstituted v-Src kinase chaperoning in vitro and show that its activation is ATP-dependent, with the cochaperone Cdc37 increasing the efficiency. Consistent with in vivo results, we find that Hsp90 does not influence the almost identical c-Src kinase. To explain these findings, we designed Src kinase chimeras that gradually transform c-Src into v-Src and show that their Hsp90 dependence correlates with compactness and folding cooperativity. Molecular dynamics simulations and hydrogen/deuterium exchange of Hsp90-dependent Src kinase variants further reveal increased transitions between inactive and active states and exposure of specific kinase regions. Thus, Hsp90 shifts an ensemble of conformations of v-Src toward high activity states that would otherwise be metastable and poorly populated.Cdc37 | kinase activation | metastable states | conformational ensembles | chaperone mechanism

show abstract

Hsp90 Chaperones

Zierer

Büchner

2012

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

Heat shock protein 90 (Hsp90) is an abundant molecular chaperone especially important in the cytosol of eukaryotic cells. Its function is coupled to large conformational rearrangements within the dimer coupled to nucleotide binding. Hsp90 assists a large set of so‐called ‘client’ proteins to stay folded or to achieve an active conformation. These client proteins include among others protein kinases and many transcription factors such as steroid hormone receptors. The function of the Hsp90 chaperone machinery itself is highly regulated on several levels. A large set of cochaperones as well as post‐translational modifications help to fine‐tune the conformational cycle. Inhibition of the low intrinsic adenosine triphosphatase (ATPase) activity of Hsp90 leads to destabilisation of its clients resulting in their degradation. As many of the clients are oncogenes, inhibition of Hsp90 is an important target in cancer therapy. Key Concepts: Hsp90 is an essential molecular chaperone in eukaryotes. Hsp90 function is coupled to nucleotide‐induced conformational changes. Hsp90 stabilises the active state of a large set of clients. Hsp90 function can be regulated via cochaperones or post‐translational modifications. Inhibition of Hsp90 is an anticancer strategy.

show abstract

Hsp90-Dependent Activation of Protein Kinases Is Regulated by Chaperone-Targeted Dephosphorylation of Cdc37

Cited by 185 publications

References 46 publications

Structural and functional basis of protein phosphatase 5 substrate specificity

Structural and functional basis of protein phosphatase 5 substrate specificity

Conformational processing of oncogenic v-Src kinase by the molecular chaperone Hsp90

Hsp90 Chaperones

Contact Info

Product

Resources

About