The Cak1p protein kinase is required at G1/S and G2/M in the budding yeast cell cycle.

The CAK1 gene encodes the major CDK-activating kinase (CAK) in budding yeast and is required for activation of Cdc28p for cell cycle progression from G2 to M phase. Here we describe the isolation of a mutant allele of CAK1 in a synthetic lethal screen with the Sit4 protein phosphatase. Analysis ...
of several different cak1 mutants shows that although the G2 to M transition appears most sensitive to loss of Cak1p function, Cak1p is also required for activation of Cdc28p for progression from G1 into S phase. Further characterization of these mutants suggests that, unlike the CAK identified from higher eukaryotes, Cak1p of budding yeast may not play a role in general transcription. Finally, although Cak1 protein levels and in vitro protein kinase activity do not fluctuate during the cell cycle, at least a fraction of Cak1p associates with higher molecular weight proteins, which may be important for its in vivo function.
Mesh Terms:
CDC28 Protein Kinase, S cerevisiae, Cell Cycle, Cyclin-Dependent Kinases, G1 Phase, G2 Phase, Genes, Fungal, Genes, Lethal, Mutation, Phosphoprotein Phosphatases, Phosphorylation, Precipitin Tests, Protein Phosphatase 2, Protein-Serine-Threonine Kinases, Proteins, RNA, Fungal, RNA, Messenger, Saccharomyces cerevisiae, Saccharomyces cerevisiae Proteins, Transcription, Genetic
Genetics
Date: Sep. 01, 1997
Download Curated Data For This Publication
18053
Switch View:
  • Interactions 1