title: Structure-function relationships of the yeast cyclin-dependent kinase Pho85.
abstract: The PHO85 gene of Saccharomyces cerevisiae encodes a cyclin-dependent kinase involved in both transcriptional regulation and cell cycle progression. Although a great deal is known concerning the structure, function, and regulation of the highly homologous Cdc28 protein kinase, little is known concerning these relationships in regard to Pho85. In this study, we constructed a series of Pho85-Cdc28 chimeras to map the region(s) of the Pho85 molecule that is critical for function of Pho85 in repression of acid phosphatase (PHO5) expression. Using a combination of site-directed and ethyl methanesulfonate-induced mutagenesis, we have identified numerous residues critical for either activation of the Pho85 kinase, interaction of Pho85 with the cyclin-like molecule Pho80, or substrate recognition. Finally, analysis of mutations analogous to those previously identified in either Cdc28 or cdc2 of Schizosaccharomyces pombe suggested that the inhibition of Pho85-Pho80 activity in mechanistically different from that seen in the other cyclin-dependent kinases.
authors.affiliation: Department of Microbiology, Medical College of Pennsylvania, Philadelphia, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Santos
authors.forename: N C
authors.initials: NC
authors.lastname: Waters
authors.forename: C L
authors.initials: CL
authors.lastname: Creasy
authors.forename: L W
authors.initials: LW
authors.lastname: Bergman
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis; D000595:Amino Acid Sequence; D017489:CDC28 Protein Kinase, S cerevisiae / Q000235:genetics / Q000378:metabolism; D017124:Conserved Sequence; D018844:Cyclin-Dependent Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism; D004794:Enzyme Repression; D005656:Fungal Proteins / Q000378:metabolism; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
chemical_list: D016213:Cyclins; D005656:Fungal Proteins; C066824:PHO80 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D017489:CDC28 Protein Kinase, S cerevisiae; D018844:Cyclin-Dependent Kinases; C058605:PHO85 protein, S cerevisiae; D000135:Acid Phosphatase