A novel S phase inhibitor in fission yeast.
We have cloned a novel fission yeast gene, spd1, which causes G1 arrest when overexpressed. Deleting the gene results in cells being accelerated through G1 into S phase in certain circumstances when the G1-->S phase control is compromised. We have found that the encoded 14 kDa protein is cell cycle regulated, declining in level during S phase, and that p14spd1 physically associates with p34cdc2 in vivo when overexpressed, suggesting that p14spd1 may regulate S phase progression via an interaction with p34cdc2. We conclude that p14spd1 is a negative regulator of S phase, and that it may be part of the control ensuring an orderly onset of S phase or part of a G1-->S phase checkpoint control.
Cell Cycle Laboratory, Imperial Cancer Research Fund, London, UK.
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Woollard
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Basi
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Nurse
D000595:Amino Acid Sequence; D001483:Base Sequence; D016203:CDC2 Protein Kinase / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D004271:DNA, Fungal; D016193:G1 Phase / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D016196:S Phase / Q000235:genetics; D012568:Schizosaccharomyces / Q000166:cytology*; D029702:Schizosaccharomyces pombe Proteins
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D029702:Schizosaccharomyces pombe Proteins; C102445:Spd1 protein, S pombe; D016203:CDC2 Protein Kinase