title: A pcl-like cyclin activates the Res2p-Cdc10p cell cycle "start" transcriptional factor complex in fission yeast.
abstract: In the fission yeast Schizosaccharomyces pombe, the "start" of the cell cycle is controlled by the two functionally redundant transcriptional regulator complexes, Res1p-Cdc10p and Res2p-Cdc10p, that activate genes essential for the onset and progression of S phase. The activity of the Res2p-Cdc10p complex is regulated at least by the availability of the Rep2 trans-activator subunit in the mitotic cell cycle. We have recently isolated the pas1(+) gene as a multicopy suppressor of the res1 null mutant. This gene encodes a novel cyclin that shares homology with the Pho85 kinase-associated cyclins of the budding yeast Saccharomyces cerevisiae. Genetic analysis reveals that Pas1 cyclin is unrelated to phosphate metabolism and stimulates the G(1)-S transition by specifically activating the Res2p-Cdc10p complex independently of Rep2p. Pas1 cyclin also controls mating pheromone signaling. Cells lacking pas1(+) are highly sensitive to mating pheromone, responding with facilitated G(1) arrest and premature commitment to conjugation. Pas1 cyclin associates in vivo with both Cdc2 and Pef1 kinases, the latter of which is a fission yeast counterpart of the budding yeast Pho85 kinase, but genetic analysis indicates that the Pef1p-associated Pas1p is responsible for the activation of Res2p-Cdc10p during the G(1)-S transition.
authors.affiliation: Department of Biochemistry and Molecular Biology, The University of Tokyo, Graduate School of Medicine, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Okayama
mesh_terms: D000074183:ATPases Associated with Diverse Cellular Activities; D000135:Acid Phosphatase / Q000378:metabolism; D000251:Adenosine Triphosphatases; D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism*; D015825:Chromosomes, Fungal / Q000235:genetics; D003227:Conjugation, Genetic; D018844:Cyclin-Dependent Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016213:Cyclins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020558:GTP Phosphohydrolases; D005838:Genotype; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008938:Mitosis; D008969:Molecular Sequence Data; D011494:Protein Kinases / Q000378:metabolism; D015183:Restriction Mapping; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D016213:Cyclins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; C490689:REP2 protein, S cerevisiae; C096254:Rep2 protein, S pombe; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; C511587:pas1 protein, S pombe; C078732:res1 protein, S pombe; C087021:res2 protein, S pombe; D011494:Protein Kinases; D018844:Cyclin-Dependent Kinases; C058605:PHO85 protein, S cerevisiae; D000135:Acid Phosphatase; D000251:Adenosine Triphosphatases; C512892:CDC10 protein, S cerevisiae; D020558:GTP Phosphohydrolases; D000074183:ATPases Associated with Diverse Cellular Activities; C511586:PEX1 protein, S cerevisiae