Abstract
The Wee1 kinase phosphorylates and inhibits cyclin-dependent kinase 1 (Cdk1), thereby delaying entry into mitosis until appropriate conditions have been met. An understanding of the mechanisms that regulate Wee1 should provide new insight into how cells make the decision to enter mitosis. We report here that Swe1, the budding-yeast homolog of Wee1, is directly regulated by Cdk1. Phosphorylation of Swe1 by Cdk1 activates Swe1 and is required for formation of a stable Swe1-Cdk1 complex that maintains Cdk1 in the inhibited state. Dephosphorylation of Cdk1 leads to further phosphorylation of Swe1 and release of Cdk1. Thus, Cdk1 both positively and negatively regulates its own inhibitor. Regulation of the Swe1-Cdk1 complex is likely to play a critical role in controlling the transition into mitosis.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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CDC2 Protein Kinase / antagonists & inhibitors
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CDC2 Protein Kinase / metabolism*
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CDC28 Protein Kinase, S cerevisiae / metabolism
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Cell Cycle Proteins / genetics
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Cell Cycle Proteins / metabolism*
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Cell Cycle Proteins / pharmacology*
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Mitosis / drug effects
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Mitosis / physiology*
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Mutation
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Phosphorylation
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Protein-Tyrosine Kinases / genetics
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Protein-Tyrosine Kinases / metabolism*
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Protein-Tyrosine Kinases / pharmacology*
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Saccharomyces cerevisiae / enzymology
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Saccharomyces cerevisiae Proteins / pharmacology*
Substances
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Cell Cycle Proteins
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Saccharomyces cerevisiae Proteins
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SWE1 protein, S cerevisiae
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Protein-Tyrosine Kinases
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CDC2 Protein Kinase
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CDC28 Protein Kinase, S cerevisiae