1. Hsp90 Phosphorylation Is Linked to Its Chaperoning Function
- Author
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Ross Gilmore, Matthew C. Coffey, Patrick W.K. Lee, Bryce Weber, Gustavo Leone, and Ya-Guang Zhao
- Subjects
biology ,Kinase ,macromolecular substances ,Cell Biology ,Geldanamycin ,Biochemistry ,Hsp90 ,Cell biology ,chemistry.chemical_compound ,chemistry ,Chaperone (protein) ,polycyclic compounds ,Protein biosynthesis ,biology.protein ,Phosphorylation ,Protein phosphorylation ,Protein folding ,Molecular Biology - Abstract
Studies on Hsp90 have mainly focused on its involvement in the activation of several families of protein kinases and of steroid hormone receptors. Little is known regarding the role of Hsp90 in the folding of nascent proteins. We previously reported that Hsp90 plays an active role in the posttranslational assembly of the C-terminal globular head of the reovirus attachment protein ς1. We show here that Hsp90 becomes phosphorylated in this process. However, only the unphosphorylated form of Hsp90 is complexed with ς1, suggesting that Hsp90 phosphorylation is coupled to the release of the chaperone from the target protein. Geldanamycin, which blocks ς1 maturation by preventing the release of Hsp90 from ς1, also inhibits Hsp90 phosphorylation. Taken together, these results demonstrate that Hsp90 phosphorylation is linked to its chaperoning function.
- Published
- 2001