Hsp90 is regulated by a switch point in the C-terminal domain

EMBO reports, 2009, 10, 1147-1153, doi:10.1038/embor.2009.153 published on 21.08.2009
EMBO reports, online article
Heat shock protein 90 (Hsp90) is an abundant, dimeric ATP-dependent molecular chaperone, and ATPase activity is essential for its in vivo functions. S-nitrosylation of a residue located in the carboxy-terminal domain has been shown to affect Hsp90 activity in vivo. To understand how variation of a specific amino acid far away from the amino-terminal ATP-binding site regulates Hsp90 functions, we mutated the corresponding residue and analysed yeast and human Hsp90 variants both in vivo and in vitro. Here, we show that this residue is a conserved, strong regulator of Hsp90 functions, including ATP hydrolysis and chaperone activity. Unexpectedly, the variants alter both the C-terminal and N-terminal association properties of Hsp90, and shift its conformational equilibrium within the ATPase cycle. Thus, S-nitrosylation of this residue allows the fast and efficient fine regulation of Hsp90.

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TU München
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Helmholtz München
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MPI of Biochemistry