mik1(+) G1-S transcription regulates mitotic entry in fission yeast

FEBS Lett. 2001 Aug 17;503(2-3):131-4. doi: 10.1016/s0014-5793(01)02720-x.


In the fission yeast Schizosaccharomyces pombe Mik1p, in combination with Wee1p, is an important inhibitor of mitosis through direct phosphorylation of Cdc2p. Here we present the observation that mik1(+) is transcribed during G1- and S-phase in normally dividing cells. mik1(+) transcription is regulated by the MCB-DSC1 system, which controls expression of other genes at the G1-S interval. mik1(+) is shown to be an important target of MCB-DSC1 as it is epistatic for the mitotic delay phenotype displayed in cdc10-C4 cells, which are mutated in a component of DSC1. The mitotic delay in cdc10-C4 cells is bypassed by cdc2-1w, suggesting that mik1(+) acts directly on cdc2(+), with no checkpoint function involved. Thus, mik1(+) represents a new type of MCB-DSC1 regulated gene in fission yeast, whose gene product is exclusively expressed during G1- and S-phase to prevent premature mitosis during this cell cycle stage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • CDC2 Protein Kinase / metabolism
  • DNA Primers / genetics
  • DNA, Fungal / genetics
  • DNA, Fungal / metabolism
  • G1 Phase / genetics
  • Gene Expression Regulation, Fungal
  • Genes, Fungal*
  • Mitosis / genetics*
  • Molecular Sequence Data
  • Phenotype
  • Promoter Regions, Genetic
  • S Phase / genetics
  • Schizosaccharomyces / cytology*
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / metabolism
  • Transcription, Genetic


  • DNA Primers
  • DNA, Fungal
  • CDC2 Protein Kinase