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Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket

[Image: see text] The stress-inducible mammalian heat shock protein 70 (HSP70) and its bacterial orthologue DnaK are highly conserved nucleotide binding molecular chaperones. They represent critical regulators of cellular proteostasis, especially during conditions of enhanced stress. Cancer cells re...

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Autores principales: Leu, Julia I-Ju, Zhang, Pingfeng, Murphy, Maureen E., Marmorstein, Ronen, George, Donna L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241170/
https://www.ncbi.nlm.nih.gov/pubmed/25148104
http://dx.doi.org/10.1021/cb500236y
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author Leu, Julia I-Ju
Zhang, Pingfeng
Murphy, Maureen E.
Marmorstein, Ronen
George, Donna L.
author_facet Leu, Julia I-Ju
Zhang, Pingfeng
Murphy, Maureen E.
Marmorstein, Ronen
George, Donna L.
author_sort Leu, Julia I-Ju
collection PubMed
description [Image: see text] The stress-inducible mammalian heat shock protein 70 (HSP70) and its bacterial orthologue DnaK are highly conserved nucleotide binding molecular chaperones. They represent critical regulators of cellular proteostasis, especially during conditions of enhanced stress. Cancer cells rely on HSP70 for survival, and this chaperone represents an attractive new therapeutic target. We have used a structure–activity approach and biophysical methods to characterize a class of inhibitors that bind to a unique allosteric site within the C-terminus of HSP70 and DnaK. Data from X-ray crystallography together with isothermal titration calorimetry, mutagenesis, and cell-based assays indicate that these inhibitors bind to a previously unappreciated allosteric pocket formed within the non-ATP-bound protein state. Moreover, binding of inhibitor alters the local protein conformation, resulting in reduced chaperone–client interactions and impairment of proteostasis. Our findings thereby provide a new chemical scaffold and target platform for both HSP70 and DnaK; these will be important tools with which to interrogate chaperone function and to aid ongoing efforts to optimize potency and efficacy in developing modulators of these chaperones for therapeutic use.
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spelling pubmed-42411702015-08-22 Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket Leu, Julia I-Ju Zhang, Pingfeng Murphy, Maureen E. Marmorstein, Ronen George, Donna L. ACS Chem Biol [Image: see text] The stress-inducible mammalian heat shock protein 70 (HSP70) and its bacterial orthologue DnaK are highly conserved nucleotide binding molecular chaperones. They represent critical regulators of cellular proteostasis, especially during conditions of enhanced stress. Cancer cells rely on HSP70 for survival, and this chaperone represents an attractive new therapeutic target. We have used a structure–activity approach and biophysical methods to characterize a class of inhibitors that bind to a unique allosteric site within the C-terminus of HSP70 and DnaK. Data from X-ray crystallography together with isothermal titration calorimetry, mutagenesis, and cell-based assays indicate that these inhibitors bind to a previously unappreciated allosteric pocket formed within the non-ATP-bound protein state. Moreover, binding of inhibitor alters the local protein conformation, resulting in reduced chaperone–client interactions and impairment of proteostasis. Our findings thereby provide a new chemical scaffold and target platform for both HSP70 and DnaK; these will be important tools with which to interrogate chaperone function and to aid ongoing efforts to optimize potency and efficacy in developing modulators of these chaperones for therapeutic use. American Chemical Society 2014-08-22 2014-11-21 /pmc/articles/PMC4241170/ /pubmed/25148104 http://dx.doi.org/10.1021/cb500236y Text en Copyright © 2014 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes.
spellingShingle Leu, Julia I-Ju
Zhang, Pingfeng
Murphy, Maureen E.
Marmorstein, Ronen
George, Donna L.
Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title_full Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title_fullStr Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title_full_unstemmed Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title_short Structural Basis for the Inhibition of HSP70 and DnaK Chaperones by Small-Molecule Targeting of a C-Terminal Allosteric Pocket
title_sort structural basis for the inhibition of hsp70 and dnak chaperones by small-molecule targeting of a c-terminal allosteric pocket
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241170/
https://www.ncbi.nlm.nih.gov/pubmed/25148104
http://dx.doi.org/10.1021/cb500236y
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