The activity of S.pombe DSC-1-like factor is cell cycle regulated and dependent on the activity of p34cdc2.
In the eukaryotic cell cycle, there are major control points in late G2 to determine the timing of the initiation of mitosis, and in late G1, regulating entry into S phase. In yeasts, this latter control is called start. Traverse of the start control and progression to S phase is accompanied by an increase in the expression of some of the genes whose products are required for DNA synthesis. In Saccharomyces cerevisiae, the coordinate expression of these genes in late G1 is dependent on a cis-acting sequence element called the MluI cell cycle box (MCB). A transcription factor called DSC-1 binds these elements and mediates cell cycle regulated transcription, though it is unclear whether this is by cell cycle-dependent changes in its activity. A DSC-1-like factor has also been identified in the fission yeast S.pombe. This is composed of at least the products of the cdc10 and sct1/res1 genes, and binds to the promoters of genes whose expression increases prior to S phase. We demonstrate that p85cdc10 is a nuclear protein and that the activity of the S.pombe DSC-1 factor varies through the cell cycle; it is high in cells that have passed start, decreases at the time of anaphase, remains low during the pre-start phase of G1 and increases at the time of the next S phase. We also show that the reactivation in late G1 is dependent on the G1 form of p34cdc2.
Reymond
A
A
Unité de Recherches sur le Cycle Cellulaire, Swiss Institute for Experimental Cancer Research (ISREC), Epalinges.
Marks
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J
Simanis
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V
D000705:Anaphase / Q000502:physiology; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000302:isolation & purification / Q000378:metabolism; D016193:G1 Phase / Q000502:physiology; D020558:GTP Phosphohydrolases; D015966:Gene Expression Regulation, Fungal; D008565:Membrane Proteins; D008954:Models, Biological; D009154:Mutation; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism; D016196:S Phase / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D008565:Membrane Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; D016203:CDC2 Protein Kinase; C512892:CDC10 protein, S cerevisiae; D020558:GTP Phosphohydrolases