Pharmacological Targeting of the Hsp70 Chaperone

Patury, Srikanth; Miyata, Yoshinari; Gestwicki, Jason E.

doi:10.2174/156802609789895674

Cited by 117 publications

(135 citation statements)

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“…Therefore targeting these specialized proteins is a viable approach to antiproliferative and antiinfective drug discovery (22)(23)(24). Nevertheless, until recently, relatively few small-molecule modulators of Hsp70 were known (20,(22)(23)(24)(25)(26).…”

Section: Resultsmentioning

confidence: 99%

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators

Huryn

Brodsky

Brummond

et al. 2011

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

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Unique chemical methodology enables the synthesis of innovative and diverse scaffolds and chemotypes and allows access to previously unexplored "chemical space." Compound collections based on such new synthetic methods can provide small-molecule probes of proteins and/or pathways whose functions are not fully understood. We describe the identification, characterization, and evolution of two such probes. In one example, a pathway-based screen for DNA damage checkpoint inhibitors identified a compound, MARPIN (ATM and ATR pathway inhibitor) that sensitizes p53-deficient cells to DNA-damaging agents. Modification of the small molecule and generation of an immobilized probe were used to selectively bind putative protein target(s) responsible for the observed activity. The second example describes a focused library approach that relied on tandem multicomponent reaction methodologies to afford a series of modulators of the heat shock protein 70 (Hsp70) molecular chaperone. The synthesis of libraries based on the structure of MAL3-101 generated a collection of chemotypes, each modulating Hsp70 function, but exhibiting divergent pharmacological activities. For example, probes that compromise the replication of a disease-associated polyomavirus were identified. These projects highlight the importance of chemical methodology development as a source of small-molecule probes and as a drug discovery starting point.ATPase | diversity oriented synthesis | isosteres | UPCMLD | alpha-methylene cyclopentenone

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Section: Resultsmentioning

confidence: 99%

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators

Huryn

Brodsky

Brummond

et al. 2011

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

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“…Escherichia coli DnaK is a member of the highly conserved heat shock protein 70 (Hsp70) 4 family, and it is involved in a variety of cellular pathways, including protein folding, transport, and degradation (1,2). As a central player in protein quality control and homeostasis, Hsp70 has also been implicated in the pathogenesis of a variety of diseases (3)(4)(5).…”

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confidence: 99%

Mutagenesis Reveals the Complex Relationships between ATPase Rate and the Chaperone Activities of Escherichia coli Heat Shock Protein 70 (Hsp70/DnaK)

Chang

Thompson

Ung

et al. 2010

Journal of Biological Chemistry

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The Escherichia coli 70-kDa heat shock protein, DnaK, is a molecular chaperone that engages in a variety of cellular activities, including the folding of proteins. During this process, DnaK binds its substrates in coordination with a catalytic ATPase cycle. Both the ATPase and protein folding activities of DnaK are stimulated by its co-chaperones, DnaJ and GrpE. However, it is not yet clear how changes in the stimulated ATPase rate of DnaK impact the folding process. In this study, we performed mutagenesis throughout the nucleotide-binding domain of DnaK to generate a collection of mutants in which the stimulated ATPase rates varied from 0.7 to 13.6 pmol/g/min ؊1 . We found that this range was largely established by differences in the ability of the mutants to be stimulated by one or both of the co-chaperones. Next, we explored how changes in ATPase rate might impact refolding of denatured luciferase in vitro and found that the two activities were poorly correlated. Unexpectedly, we found several mutants that refold luciferase normally in the absence of significant ATP turnover, presumably by increasing the flexibility of DnaK. Finally, we tested whether DnaK mutants could complement growth of ⌬dnaK E. coli cells under heat shock and found that the ability to refold luciferase was more predictive of in vivo activity than ATPase rate. This study provides insights into how flexibility and co-chaperone interactions affect DnaK-mediated ATP turnover and protein folding.Escherichia coli DnaK is a member of the highly conserved heat shock protein 70 (Hsp70) 4 family, and it is involved in a variety of cellular pathways, including protein folding, transport, and degradation (1, 2). As a central player in protein quality control and homeostasis, Hsp70 has also been implicated in the pathogenesis of a variety of diseases (3-5). These observations have led to an interest in understanding how the various activities of Hsp70 are correlated.One of the main roles of DnaK is to enable the folding of nascent or otherwise unfolded proteins (6). In this role, DnaK is thought to limit aggregation and facilitate folding by binding to the hydrophobic regions exposed in these substrates. Briefly, DnaK, like all the Hsp70 family members, consists of a substrate-binding domain (SBD) and a nucleotide-binding domain (NBD) connected by a hydrophobic linker (7-9). The NBD of DnaK is further divided into four subdomains as follows: IA/IIA, which form the base, and IB/IIB, which form the upper walls of the nucleotide binding cleft (Fig. 1A). The binding of ATP to DnaK results in an "open" conformation with low substrate affinity. Upon hydrolysis, the ADP-bound form assumes a "closed" conformation that binds substrate with higher affinity (10 -16). Thus, allosteric communication between the two domains is thought to link nucleotide turnover to substrate binding and release.DnaK alone has a low intrinsic ATPase rate, which facilitates regulation by the important co-chaperones, DnaJ and GrpE. DnaJ specifically stimulates ATP hydrolysis and thus...

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“…Thus, J proteins are expected to promote tight binding of Hsp70s to their substrates and these co-chaperones have been found to play multiple roles during protein aggregation (21,32). Thus, one promising approach to chemically controlling the activities of Hsp70s may be to selectively target the interaction with the J proteins (8,33). Toward that goal, the Brodsky group originally identified dihydropyrimidines as chemical reagents for specifically promoting the J-stimulated activity of Hsp70s (34,35).…”

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confidence: 99%

Ordered Assembly of Heat Shock Proteins, Hsp26, Hsp70, Hsp90, and Hsp104, on Expanded Polyglutamine Fragments Revealed by Chemical Probes

Walter

Smith

Wisén

et al. 2011

Journal of Biological Chemistry

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In Saccharomyces cerevisae, expanded polyglutamine (polyQ) fragments are assembled into discrete cytosolic aggregates in a process regulated by the molecular chaperones Hsp26, Hsp70, Hsp90, and Hsp104. To better understand how the different chaperones might cooperate during polyQ aggregation, we used sequential immunoprecipitations and mass spectrometry to identify proteins associated with either soluble (Q25) or aggregation-prone (Q103) fragments at both early and later times after induction of their expression. We found that Hsp26, Hsp70, Hsp90, and other chaperones interact with Q103, but not Q25, within the first 2 h. Further, Hsp70 and Hsp90 appear to be partially released from Q103 prior to the maturation of the aggregates and before the recruitment of Hsp104. To test the importance of this seemingly ordered process, we used a chemical probe to artificially enhance Hsp70 binding to Q103. This treatment retained both Hsp70 and Hsp90 on the polyQ fragment and, interestingly, limited subsequent exchange for Hsp26 and Hsp104, resulting in incomplete aggregation. Together, these results suggest that partial release of Hsp70 may be an essential step in the continued processing of expanded polyQ fragments in yeast.The heat shock proteins (HSPs) 3 are abundant molecular chaperones that have been shown to be important for maintaining proteostasis under both normal conditions and during times of cellular stress (1-3). Together, these factors play multiple roles in quality control, especially related to polypeptide synthesis, folding, and turnover (4 -7). Moreover, HSPs are emerging as drug targets in cancer, neurodegenerative disorders and other diseases (8, 9). Thus, there is interest in better understanding how they coordinate protein quality control decisions.The major families of HSPs are named based on their approximate kDa molecular weights, including Hsp60, Hsp70, Hsp90,

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Pharmacological Targeting of the Hsp70 Chaperone

Cited by 117 publications

References 181 publications

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators

Chemical methodology as a source of small-molecule checkpoint inhibitors and heat shock protein 70 (Hsp70) modulators

Mutagenesis Reveals the Complex Relationships between ATPase Rate and the Chaperone Activities of Escherichia coli Heat Shock Protein 70 (Hsp70/DnaK)

Ordered Assembly of Heat Shock Proteins, Hsp26, Hsp70, Hsp90, and Hsp104, on Expanded Polyglutamine Fragments Revealed by Chemical Probes

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