Positive and negative roles for cdc10 in cell cycle gene expression

Nucleic Acids Res. 1995 Dec 11;23(23):4761-8. doi: 10.1093/nar/23.23.4761.


In this paper we describe properties of the cdc10-C4 mutant of the fission yeast Schizosaccharomyces pombe. The cdc10+ gene encodes a component of the DSC1Sp/MBF transcription complex, which is required for cell-cycle regulated expression at G1-S of several genes via cis-acting MCB (MIuI cell cycle box) elements. At permissive temperatures cdc10-C4 causes expression of MCB-regulated genes through the whole cell cycle, which in asynchronously dividing cells is manifested in overall higher expression levels. This overexpression phenotype is cold sensitive: in cdc10-C4 cells, MCB genes are expressed offprogressively higher levels at lower temperatures. In heterozygous cdc10-C4/cdc10+ diploid strains, MCB-regulated genes are not overexpressed, suggesting that loss, rather than alteration, of function of the cdc10-C4 gene product is the reason for unregulated target gene expression. Consistent with this, the cdc10-C4 mutant allele is known to encode a truncated protein. We have also overexpressed the region of the cdc10 protein absent in cdc10-C4 under the control of an inducible promoter. This induces a G1 delay, and additionally causes a reduction of the overexpression of MCB genes in cdc10-C4 strains. These results suggest that DSC1Sp/MBF represses, as well as activates, MCB gene expression during the cell cycle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Cycle / genetics*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • G1 Phase / genetics
  • G2 Phase / genetics
  • Gene Expression Regulation, Fungal / genetics*
  • Genes, Fungal / genetics*
  • Genes, Fungal / physiology
  • Genes, Recessive
  • Molecular Sequence Data
  • Mutation / genetics
  • Schizosaccharomyces / cytology
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / physiology
  • Temperature
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Fungal Proteins
  • Transcription Factors