title: Systematic Mutant Analyses Elucidate General and Client-Specific Aspects of Hsp90 Function.
abstract: To probe the mechanism of the Hsp90 chaperone that is required for the maturation of many signaling proteins in eukaryotes, we analyzed the effects of all individual amino acid changes in the ATPase domain on yeast growth rate. The sensitivity of a position to mutation was strongly influenced by proximity to the phosphates of ATP, indicating that ATPase-driven conformational changes impose stringent physical constraints on Hsp90. To investigate how these constraints may vary for different clients, we performed biochemical analyses on a panel of Hsp90 mutants spanning the full range of observed fitness effects. We observed distinct effects of nine Hsp90 mutations on activation of v-src and glucocorticoid receptor (GR), indicating that different chaperone mechanisms can be utilized for these clients. These results provide a detailed guide for understanding Hsp90 mechanism and highlight the potential for inhibitors of Hsp90 that target a subset of clients.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Parul
authors.initials: P
authors.lastname: Mishra
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Flynn
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Tyler N
authors.initials: TN
authors.lastname: Starr
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA. Electronic address: dan.bolon@umassmed.edu.
authors.forename: Daniel N A
authors.initials: DNA
authors.lastname: Bolon
mesh_terms: D000225:Adenine / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000596:Amino Acids / Q000235:genetics; D017124:Conserved Sequence; D019143:Evolution, Molecular; D056084:Genetic Fitness; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D018841:HSP90 Heat-Shock Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D000225:Adenine