Fission yeast p107wee1 mitotic inhibitor is a tyrosine/serine kinase

Nature. 1991 Feb 28;349(6312):808-11. doi: 10.1038/349808a0.


The fission yeast wee1+ gene product is a dose-dependent, negative regulator of entry into mitosis. wee1+ encodes a protein of relative molecular mass 107,000 (Mr 107K), the C-terminal third of which has strong similarities with the serine/threonine protein kinase family. Here we report that p107wee1 immune complexes phosphorylate p107wee1 equally on serine and tyrosine residues, and also phosphorylate an exogenous substrate, angiotensin II, on tyrosine. Both kinase activities are attributable to p107wee1 because they are also observed when wee1+ is expressed in heterologous systems; both are abolished by a point mutation in the ATP-binding domain, and both behave like an asymmetric monomer of Mr114K on gel filtration and density-gradient centrifugation. Thus the wee1+ gene product is representative of a novel class of protein kinase that phosphorylates both serine and tyrosine residues.

Publication types

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

MeSH terms

  • Animals
  • Baculoviridae / genetics
  • Cell Line
  • Genes, Fungal*
  • Insecta
  • Kinetics
  • Mitosis*
  • Phosphorylation
  • Protein Kinases / genetics
  • Protein Kinases / isolation & purification
  • Protein Kinases / metabolism*
  • Protein-Serine-Threonine Kinases
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / isolation & purification
  • Protein-Tyrosine Kinases / metabolism*
  • Schizosaccharomyces / cytology
  • Schizosaccharomyces / enzymology*
  • Schizosaccharomyces / genetics
  • Transfection


  • Protein Kinases
  • Protein-Tyrosine Kinases
  • Protein-Serine-Threonine Kinases