The Mechanism of Hsp90 Regulation by the Protein Kinase-Specific Cochaperone p50cdc37

Roe, S. Mark; Ali, Maruf M. U.; Meyer, Philippe; Vaughan, Cara K.; Panaretou, Barry; Piper, Peter W.; Prodromou, Chrisostomos; Pearl, Laurence H.

doi:10.1016/s0092-8674(03)01027-4

Cited by 319 publications

(397 citation statements)

References 61 publications

Supporting

Mentioning

376

Contrasting

Unclassified

Order By: Relevance

“…Comparison with Hsp90 -Although both GRP94 and Hsp90 bind ATP/ADP, the conformation of nucleotide-bound GRP94 differs from that of any of the previously determined structures of Hsp90 (6,8,9,11,35,37). As seen from the superposition in Fig.…”

Section: Grp94-atp Structurementioning

confidence: 82%

Ligand-induced Conformational Shift in the N-terminal Domain of GRP94, an Hsp90 Chaperone

Immormino¹,

Dollins²,

Shaffer

et al. 2004

Journal of Biological Chemistry

129

View full text Add to dashboard Cite

The hsp90 1 family of molecular chaperones is required for the activation of a large number of proteins, including those involved in eukaryotic cell cycle regulation, signal transduction, immune response, and transcription (1, 2). GRP94 (also known as gp96), the endoplasmic reticulum paralog of cytoplasmic Hsp90, participates in the maturation of proteins that are transported to the cell surface, including Toll-like receptors and certain integrins (3), or secreted, such as IgGs (4, 5). The activity of the hsp90 family chaperones is regulated by ATP (6). Fungally derived ansamycin antibiotics such as geldanamycin and radicicol (7) compete for the ATP binding site (8 -11) and exhibit potent anti-tumor activity by acting as pan-hsp90 inhibitors (12-17). Given their central importance in the biology of protein folding and in cellular stress response, and their potential as targets in a variety of therapeutic strategies, the mechanism by which hsp90 chaperone activity is regulated and the chemistry of their interactions with client substrates are under intensive investigation.GRP94 and Hsp90 exist as obligate homodimers, with each subunit consisting of an N-terminal regulatory and ligand binding domain, a charged region, a middle domain, and a C-terminal dimerization domain. This organization and the structural similarity of their N-terminal ATP binding domains characterize the GHKL family of proteins (18), whose members in addition to Hsp90s also include DNA gyrase, histidine kinases, DNA topoisomerase II, and MutL. By analogy to DNA gyrase (19) and MutL (20), it has been proposed that Hsp90 chaperone activity is linked to an N-domain conformational change that is coupled to ATP binding and hydrolysis and that results in the dimerization of the N-domains (21, 22). Mechanistic explanations of how ATP binding and hydrolysis are coupled to Hsp90 activity have been hindered, however, by the lack of any observed change in the conformation of the Ndomain in response to ligands. The complete protein, rather than just the isolated N-domain, is required for ATP hydrolysis (6, 23), suggesting that conformational rearrangements resulting in a close interaction between the N-and middle domains are important for Hsp90 activity. Interactions with co-chaperones may also be important catalysts for ATP hydrolysis in human Hsp90 as well (24).GRP94 and Hsp90 are greater than 50% identical in their N-domains, yet the biochemical hallmarks of Hsp90 chaperone activity are largely missing for this paralog. ATP hydrolysis above background levels has not been detected for GRP94 (25), nor have co-chaperones or partner proteins been identified. In addition, although Hsp90 binds ADP/ATP with micromolar affinity (11), the binding constant for adenosine nucleotides to GRP94 is estimated to be of several millimolar units (25). These differences suggest that the structure of GRP94 may reveal an alternative regulatory mechanism for GRP94. The structure of the N-domain of GRP94 in complex with a series of inhibitory ligands was reported recently and...

show abstract

Section: Grp94-atp Structurementioning

confidence: 82%

Ligand-induced Conformational Shift in the N-terminal Domain of GRP94, an Hsp90 Chaperone

Immormino¹,

Dollins²,

Shaffer

et al. 2004

Journal of Biological Chemistry

129

View full text Add to dashboard Cite

show abstract

“…Our data and previous studies may explain the sequence of chaperoning cycles in Hsp90 superchaperone complex. The previous results have shown that the COOH terminus of Cdc37 inserts into the ATP-binding pocket of Hsp90 (open state), later ATP binding to Hsp90 ejects Cdc37 from Hsp90 (14), setting up the stage for binding of p23 to Hsp90. Therefore, Cdc37 and p23 bind to Hsp90 at different stages of the chaperoning cycle without coexisting in one complex.…”

Section: Discussionmentioning

confidence: 95%

“…The recent structural study of Hsp90/Cdc37 has shown that Cdc37 binds to the NH 2 -terminal domain of Hsp90 by inserting its COOHterminal side chain into the nucleotide-binding pocket, holding Hsp90 in an ''open'' conformation (14). Therefore, progression from this stage through the ATPase cycle requires the ejection of Cdc37 side chain from the binding pocket (14). In vitro protein binding analysis also suggests that binding of Cdc37 and p23 to Hsp90 is mutually exclusive and the p23-Hsp90-Cdc37 complex could not exist (24).…”

Section: Discussionmentioning

confidence: 99%

“…Our data are in agreement with the recent crystal structure of Hsp90/ Cdc37 and Hsp90/p23. The structural analysis has revealed that Cdc37 binds to the NH 2 -terminal binding domain of Hsp90 and arrests the chaperoning cycle in the conformation that could inhibit the binding of p23 to Hsp90 (14). Subsequently, in vitro difference circular dichroism suggests that binding of p23 and Cdc37 to Hsp90 is mutually exclusive (24).…”

Section: P23 Does Not Coexist With Cdc37 or Hopmentioning

confidence: 99%

See 1 more Smart Citation

A novel Hsp90 inhibitor to disrupt Hsp90/Cdc37 complex against pancreatic cancer cells

Zhang

Hamza

Cao

et al. 2008

Molecular Cancer Therapeutics

337

320

View full text Add to dashboard Cite

Pancreatic cancer is an aggressive disease with multiple biochemical and genetic alterations. Thus, a single agent to hit one molecular target may not be sufficient to treat this disease. The purpose of this study is to identify a novel Hsp90 inhibitor to disrupt protein-protein interactions of Hsp90 and its cochaperones for down-regulating many oncogenes simultaneously against pancreatic cancer cells. Here, we reported that celastrol disrupted Hsp90-Cdc37 interaction in the superchaperone complex to exhibit antitumor activity in vitro and in vivo. Molecular docking and molecular dynamic simulations showed that celastrol blocked the critical interaction of Glu 33 (Hsp90) and Arg 167 (Cdc37). Immunoprecipitation confirmed that celastrol (10 Mmol/L) disrupted the Hsp90-Cdc37 interaction in the pancreatic cancer cell line Panc-1. In contrast to classic Hsp90 inhibitor (geldanamycin), celastrol (0.1-100 Mmol/L) did not interfere with ATP binding to Hsp90. However, celastrol (1-5 Mmol/L) induced Hsp90 client protein degradation (Cdk4 and Akt) by 70% to 80% and increased Hsp70 expression by 12-fold. Celastrol induced apoptosis in vitro and significantly inhibited tumor growth in Panc-1 xenografts. Moreover, celastrol (3 mg/kg) effectively suppressed tumor metastasis by more than 80% in RIP1-Tag2 transgenic mouse model with pancreatic islet cell carcinogenesis. The data suggest that celastrol is a novel Hsp90 inhibitor to disrupt Hsp90-Cdc37 interaction against pancreatic cancer cells.

show abstract

“…Besides the known Hsp90 partners, two tetratricopeptide repeat (TPR)-domain-containing proteins, Ttc1 and FLJ21908, were isolated with immobilized Hsp90CT, which was consistent with the design of the assay. Although the use of Hsp90CT excludes the specific isolation of Cdc37, which binds to the N-domain of Hsp90 (Roe et al 2004), immunoprecipitation also failed to isolate Cdc37 (Te et al 2007). Notably, Falsone et al could not coimmunoprecipitate Cdc37, which may have resulted from overlapping binding sites of the antibody and Cdc37 on Hsp90 (Falsone et al 2005).…”

Section: Discussionmentioning

confidence: 99%

Novel Hsp90 partners discovered using complementary proteomic approaches

Tsaytler

Krijgsveld

Goerdayal

et al. 2009

Cell Stress and Chaperones

View full text Add to dashboard Cite

Hsp90 is an essential eukaryotic molecular chaperone that stabilizes a large set of client proteins, many of which are involved in various cellular signaling pathways. The current list of Hsp90 interactors comprises about 200 proteins and this number is growing steadily. In this paper, we report on the application of three complementary proteomic approaches directed towards identification of novel proteins that interact with Hsp90. These methods are coimmunoprecipitation, pull down with biotinylated geldanamycin, and immobilization of Hsp90β on sepharose. In all, this study led to the identification of 42 proteins, including 18 proteins that had not been previously characterized as Hsp90 interactors. These novel Hsp90 partners not only represent abundant protein species, but several proteins were identified at low levels, among which signaling kinase Cdk3 and putative transcription factor tripartite motif-containing protein 29. Identification of tetratricopeptide-repeat-containing mitochondrial import receptor protein Tom34 suggests the involvement of Hsp90 in the early steps of translocation of mitochondrial preproteins. Taken together, our data expand the knowledge of the Hsp90 interactome and provide a further step in our understanding of the Hsp90 chaperone system.

show abstract

The Mechanism of Hsp90 Regulation by the Protein Kinase-Specific Cochaperone p50cdc37

Cited by 319 publications

References 61 publications

Ligand-induced Conformational Shift in the N-terminal Domain of GRP94, an Hsp90 Chaperone

Ligand-induced Conformational Shift in the N-terminal Domain of GRP94, an Hsp90 Chaperone

A novel Hsp90 inhibitor to disrupt Hsp90/Cdc37 complex against pancreatic cancer cells

Novel Hsp90 partners discovered using complementary proteomic approaches

Contact Info

Product

Resources

About