Characterization of the 90 kDa heat shock protein (HSP90)-associated ATP/GTPase

Gábor Nardai, Tamás Schnaider, Csaba Söti, Michael T. Ryan, Peter B. Hoj, János Somogyi, Peter Csermely

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21 Citations (Scopus)

Abstract

The 90 kDa heat shock protein (HSP90) is an ATP-binding molecular chaperone with an associated ATPase activity having nucleoplasmin and HSP70-binding homology domains and containing Ca-binding EF-hands and a nuclear localization signal. Here we characterize the HSP90-associated ATPase and show that it is (i) a P-type ATPase inhibited by molybdate and vanadate, (ii) able to hydrolyze methylfluorescein phosphate with a 5-6-fold higher affinity, (iii) a 3-times better GTPase than ATPase in the presence of calcium and (iv) HSP27 and F-actin, but not HSP10 can "convert" the HSP90-associated ATPase activity to HSP90 autokinase activity. The HSP90-associated ATP/GTPase may participate in the regulation of complex formation of HSP90 with other proteins, such as F-actin, tubulin and heat shock proteins.

Original languageEnglish
Pages (from-to)179-190
Number of pages12
JournalJournal of Biosciences
Volume21
Issue number2
DOIs
Publication statusPublished - 1 Apr 1996
Externally publishedYes

Keywords

  • HSP10
  • HSP27
  • methylfluorescein phosphate
  • Molecular chaperone
  • molybdate
  • Vanadate

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