The mitotic inducer nim1+ functions in a regulatory network of protein kinase homologs controlling the initiation of mitosis

Cell. 1987 May 22;49(4):569-76. doi: 10.1016/0092-8674(87)90459-4.


The newly discovered fission yeast mitotic control element nim1+ (new inducer of mitosis) is the first dose-dependent mitotic inducer identified as a protein kinase homolog. Increased nim1+ expression rescues mutants lacking the mitotic inducer cdc25+ and advances cells into mitosis at a reduced cell size; loss of nim1+ delays mitosis until cells have grown to a larger size. The nim1+ gene potentially encodes a 50 kd protein that contains the consensus sequences of protein kinases. Genetic evidence indicates that nim1+ is a negative regulator of the wee1+ mitotic inhibitor, another protein kinase homolog. The combined mitotic induction activities of nim1+ and cdc25+ counteract the wee1+ mitotic inhibitor in a regulatory network that appears also to involve the cdc2+ protein kinase, which is required for mitosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Base Sequence
  • Genes*
  • Genes, Fungal*
  • Genes, Regulator*
  • Genotype
  • Mitosis
  • Mutation
  • Protein Kinases / genetics*
  • Saccharomycetales / genetics*
  • Schizosaccharomyces / cytology
  • Schizosaccharomyces / enzymology
  • Schizosaccharomyces / genetics*
  • Sequence Homology, Nucleic Acid


  • Protein Kinases

Associated data

  • GENBANK/M16509