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In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis

Heat shock protein 90 (Hsp90), an abundant molecular chaperone in the eukaryotic cytosol, is involved in the folding of a set of cell regulatory proteins and in the re-folding of stress-denatured polypeptides. The basic mechanism of action of Hsp90 is not yet understood. In particular, it has been d...

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Autores principales: Obermann, Wolfgang M.J., Sondermann, Holger, Russo, Alicia A., Pavletich, Nikola P., Hartl, F. Ulrich
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1998
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132952/
https://www.ncbi.nlm.nih.gov/pubmed/9817749
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author Obermann, Wolfgang M.J.
Sondermann, Holger
Russo, Alicia A.
Pavletich, Nikola P.
Hartl, F. Ulrich
author_facet Obermann, Wolfgang M.J.
Sondermann, Holger
Russo, Alicia A.
Pavletich, Nikola P.
Hartl, F. Ulrich
author_sort Obermann, Wolfgang M.J.
collection PubMed
description Heat shock protein 90 (Hsp90), an abundant molecular chaperone in the eukaryotic cytosol, is involved in the folding of a set of cell regulatory proteins and in the re-folding of stress-denatured polypeptides. The basic mechanism of action of Hsp90 is not yet understood. In particular, it has been debated whether Hsp90 function is ATP dependent. A recent crystal structure of the NH(2)-terminal domain of yeast Hsp90 established the presence of a conserved nucleotide binding site that is identical with the binding site of geldanamycin, a specific inhibitor of Hsp90. The functional significance of nucleotide binding by Hsp90 has remained unclear. Here we present evidence for a slow but clearly detectable ATPase activity in purified Hsp90. Based on a new crystal structure of the NH(2)-terminal domain of human Hsp90 with bound ADP-Mg and on the structural homology of this domain with the ATPase domain of Escherichia coli DNA gyrase, the residues of Hsp90 critical in ATP binding (D93) and ATP hydrolysis (E47) were identified. The corresponding mutations were made in the yeast Hsp90 homologue, Hsp82, and tested for their ability to functionally replace wild-type Hsp82. Our results show that both ATP binding and hydrolysis are required for Hsp82 function in vivo. The mutant Hsp90 proteins tested are defective in the binding and ATP hydrolysis–dependent cycling of the co-chaperone p23, which is thought to regulate the binding and release of substrate polypeptide from Hsp90. Remarkably, the complete Hsp90 protein is required for ATPase activity and for the interaction with p23, suggesting an intricate allosteric communication between the domains of the Hsp90 dimer. Our results establish Hsp90 as an ATP-dependent chaperone.
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spelling pubmed-21329522008-05-01 In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis Obermann, Wolfgang M.J. Sondermann, Holger Russo, Alicia A. Pavletich, Nikola P. Hartl, F. Ulrich J Cell Biol Regular Articles Heat shock protein 90 (Hsp90), an abundant molecular chaperone in the eukaryotic cytosol, is involved in the folding of a set of cell regulatory proteins and in the re-folding of stress-denatured polypeptides. The basic mechanism of action of Hsp90 is not yet understood. In particular, it has been debated whether Hsp90 function is ATP dependent. A recent crystal structure of the NH(2)-terminal domain of yeast Hsp90 established the presence of a conserved nucleotide binding site that is identical with the binding site of geldanamycin, a specific inhibitor of Hsp90. The functional significance of nucleotide binding by Hsp90 has remained unclear. Here we present evidence for a slow but clearly detectable ATPase activity in purified Hsp90. Based on a new crystal structure of the NH(2)-terminal domain of human Hsp90 with bound ADP-Mg and on the structural homology of this domain with the ATPase domain of Escherichia coli DNA gyrase, the residues of Hsp90 critical in ATP binding (D93) and ATP hydrolysis (E47) were identified. The corresponding mutations were made in the yeast Hsp90 homologue, Hsp82, and tested for their ability to functionally replace wild-type Hsp82. Our results show that both ATP binding and hydrolysis are required for Hsp82 function in vivo. The mutant Hsp90 proteins tested are defective in the binding and ATP hydrolysis–dependent cycling of the co-chaperone p23, which is thought to regulate the binding and release of substrate polypeptide from Hsp90. Remarkably, the complete Hsp90 protein is required for ATPase activity and for the interaction with p23, suggesting an intricate allosteric communication between the domains of the Hsp90 dimer. Our results establish Hsp90 as an ATP-dependent chaperone. The Rockefeller University Press 1998-11-16 /pmc/articles/PMC2132952/ /pubmed/9817749 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Regular Articles
Obermann, Wolfgang M.J.
Sondermann, Holger
Russo, Alicia A.
Pavletich, Nikola P.
Hartl, F. Ulrich
In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title_full In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title_fullStr In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title_full_unstemmed In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title_short In Vivo Function of Hsp90 Is Dependent on ATP Binding and ATP Hydrolysis
title_sort in vivo function of hsp90 is dependent on atp binding and atp hydrolysis
topic Regular Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2132952/
https://www.ncbi.nlm.nih.gov/pubmed/9817749
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