Open AccessHsp90 chaperone complexes are required for the activity and stability of yeast protein kinases Mik1, Wee1 and Swe1
Author(s) -
Goes Fernando S.,
Martin Jörg
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02105.x
Subject(s) - wee1 , hsp90 , cdc37 , cyclin dependent kinase 1 , microbiology and biotechnology , schizosaccharomyces pombe , kinase , biology , geldanamycin , cyclin dependent kinase complex , saccharomyces cerevisiae , protein kinase a , biochemistry , yeast , cyclin dependent kinase 2 , cell cycle , heat shock protein , cell , extracellular signal regulated kinases , gene
The Wee1 protein kinase negatively regulates entry into mitosis by mediating the inhibitory tyrosine phosphorylation of Cdc2‐cyclin B kinase. The stability and activity of Wee1 from the fission yeast Schizosaccharomyces pombe is critically dependent on functional Hsp90 chaperones. Here we identify two related tyrosine protein kinases, Mik1 from fission yeast and its Saccharomyces cerevisiae homolog Swe1, as Hsp90 substrates and show that the kinase domain is sufficient to mediate this interaction. Morphological and biochemical defects arising from overexpression of the kinases in fission yeast are suppressed in the conditional Hsp90 mutant swo1‐26 . A subset of all three kinases is associated with the Hsp90 cochaperones cyclophilin 40 and p23. Under conditions of impaired chaperone function or treatment with the Hsp90 inhibitory drug geldanamycin, intracellular levels of the kinases are reduced and the proteins become rapidly degraded by the proteasome machinery, indicating that Wee1, Mik1 and Swe1 require Hsp90 heterocomplexes for their stability and maintenance of function.