Cell-cycle control linked to extracellular environment by MAP kinase pathway in fission yeast

Nature. 1995 Dec 14;378(6558):739-43. doi: 10.1038/378739a0.


In fission yeast the onset of mitosis is brought about by Cdc2/Cdc13 kinase, which is inhibited by the Wee1/Mik1 tyrosine kinases and activated by Cdc25 tyrosine phosphatase. This control network integrates many signals, including those that monitor DNA replication, DNA damage and cell size. We report here that a fission yeast MAP kinase pathway links the cell-cycle G2/M control with changes in the extracellular environment that affect cell physiology. Fission yeast spc1- mutants have a G2 delay that is greatly exacerbated by growth in high osmolarity media and nutrient limitation. A lethal interaction of spc1 and cdc25 mutations shows that Spc1 promotes the onset of mitosis. Spc1 is a MAP kinase homologue that is activated by Wis1 kinase in response to osmotic stress and nutrient limitation. Spc1 is inactivated by Pyp1, a phosphatase previously identified as a mitotic inhibitor. Pyp1 dephosphorylates only tyrosine-173 of Spc1, unlike the dual-specificity phosphatases that have been shown to regulate other MAP kinases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Calcium-Calmodulin-Dependent Protein Kinases / antagonists & inhibitors
  • Calcium-Calmodulin-Dependent Protein Kinases / genetics
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
  • Cell Cycle / physiology*
  • Cell Cycle Proteins
  • Cloning, Molecular
  • DNA Primers
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism*
  • Molecular Sequence Data
  • Mutation
  • Phosphorylation
  • Protein Tyrosine Phosphatases / metabolism
  • Schizosaccharomyces / cytology*
  • Schizosaccharomyces / enzymology
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism*
  • Sequence Homology, Amino Acid
  • Tyrosine / metabolism


  • Cell Cycle Proteins
  • DNA Primers
  • Schizosaccharomyces pombe Proteins
  • Tyrosine
  • Calcium-Calmodulin-Dependent Protein Kinases
  • Mitogen-Activated Protein Kinases
  • Spc1 protein, S pombe
  • sty1 protein, S pombe
  • Protein Tyrosine Phosphatases
  • pyp1 protein, S pombe

Associated data

  • GENBANK/L06279
  • GENBANK/L35253
  • GENBANK/U26739
  • GENBANK/X57334
  • GENBANK/X80751