Fission yeast cut5+, required for S phase onset and M phase restraint, is identical to the radiation-damage repair gene rad4+.
Fission yeast cut5 mutants cause cytokinesis in the absence of normal nuclear division. We show here that cut5+ is required for both the onset of S phase and the restraint of M phase before the completion of S phase. The primary defects in cut5 mutants occur prior to S phase, but cells suffer lethal damage during M phase. Mitosis and cytokinesis occur in the presence of hydroxyurea or in the double mutant cdc10-cut5 (the cdc10 mutation alone blocks progression from G1 to S). Gene cloning shows that cut5+ is identical to the fission yeast rad4+ gene, which is similar to human XRCC1. The rad4+/cut5+ gene is unique in its positive role for replication/repair and in its negative role for mitosis/cytokinesis. We propose a single/twin chromatid marking model for rad4+/cut5+ function in cell cycle control.
Saka
Y
Y
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
Yanagida
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000235:genetics; D002467:Cell Nucleus; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000096:biosynthesis; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics* / Q000528:radiation effects; D008938:Mitosis / Q000235:genetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000172:deficiency; D010641:Phenotype; D016196:S Phase / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics* / Q000528:radiation effects; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; D014170:Transformation, Genetic; D011503:Transglutaminases; D014466:Ultraviolet Rays / Q000009:adverse effects; D014965:X-Rays / Q000009:adverse effects
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C082463:RAD4 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; D011503:Transglutaminases; D009584:Nitrogen