Phosphorylation of the transcription factor PHO4 by a cyclin-CDK complex, PHO80-PHO85.
Induction of the yeast gene PHO5 is mediated by the transcription factors PHO2 and PHO4. PHO5 transcription is not detectable in high phosphate; it is thought that the negative regulators PHO80 and PHO85 inactivate PHO2 and PHO4. Here it is reported that PHO80 has homology to yeast cyclins and interacts with PHO85, a p34cdc2/CDC28-related protein kinase. The PHO80-PHO85 complex phosphorylates PHO4; this phosphorylation is correlated with negative regulation of PHO5. These results demonstrate the existence of a cyclin-cdk complex that is used for a regulatory process other than cell-cycle control and identify a physiologically relevant substrate for this complex.
Kaffman
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School of Medicine, Department of Biochemistry and Biophysics, University of California at San Francisco 94143.
Herskowitz
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Tjian
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O'Shea
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EK
D000135:Acid Phosphatase / Q000096:biosynthesis* / Q000235:genetics; D000595:Amino Acid Sequence; D003470:Culture Media; D018844:Cyclin-Dependent Kinases; D016213:Cyclins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism; D010766:Phosphorylation; D012097:Repressor Proteins / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors
D003470:Culture Media; D016213:Cyclins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C060292:PHO4 protein, S cerevisiae; C066824:PHO80 protein, S cerevisiae; D010710:Phosphates; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D018844:Cyclin-Dependent Kinases; C058605:PHO85 protein, S cerevisiae; D000135:Acid Phosphatase