pct1+, which encodes a new DNA-binding partner of p85cdc10, is required for meiosis in the fission yeast Schizosaccharomyces pombe.
The transcriptional activation of genes at late G1 is an important regulatory step in the commitment to a new cell division cycle. In Schizosaccharomyces pombe, this regulation is mediated by MCB elements that serve as binding sites for the MBF/DSC-1 complex. The cdc10(+)-encoded protein is a component of this complex. We report the cloning of a new gene, pct1+, encoding a 73-kD protein that interacts with p85cdc10 to form an MCB-binding heteromer. Pct1+ is related to, but distinct from, the res1+/sct1+ gene that also encodes a p85cdc10 partner. p73pct1 has centrally located ankyrin repeats and a putative amino-terminal DNA-binding domain that has extensive sequence similarity to the DNA-binding domains of the Saccharomyces cerevisiae SWI4 and MBP1 proteins. The p73pct1/p85cdc10 complex binds both in vitro and in vivo to MCB but not SCB or E2F sites. Overexpression of pct1+ is sufficient to rescue the growth of the cdc10-129 temperature-sensitive mutant at the restrictive temperature, although it is unable to rescue a cdc10 null mutation. A deletion of pct1+ is not lethal but does result in a severe meiotic defect. Our results indicate that there are two cdc10-containing heteromeric complexes that bind to MCB elements and play differential roles in mitotic division and meiosis.
Zhu
Y
Y
Laboratory of Gene Regulation, Imperial Cancer Research Fund, London, UK.
Takeda
T
T
Nasmyth
K
K
Jones
N
N
D000595:Amino Acid Sequence; D001483:Base Sequence; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D016213:Cyclins; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism*; D020558:GTP Phosphohydrolases; D005800:Genes, Fungal / Q000235:genetics*; D008540:Meiosis / Q000235:genetics*; D008565:Membrane Proteins; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; D016213:Cyclins; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C083209:MBP1 protein, S cerevisiae; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; C087021:res2 protein, S pombe; C070839:PCL1 protein, S cerevisiae; C512892:CDC10 protein, S cerevisiae; D020558:GTP Phosphohydrolases