A kinase from fission yeast responsible for blocking mitosis in S phase

Nature. 1995 Apr 27;374(6525):817-9. doi: 10.1038/374817a0.


In virtually all eukaryotes, mitosis starts after the completion of DNA synthesis. This orderly process is ensured by the checkpoint mechanism that blocks the onset of mitosis while DNA is being synthesized or is damaged. In the fission yeast Schizosaccharomyces pombe, this mechanism involves some rad+ and hus+ genes. However, it is not known how the checkpoint system monitors these events. Recently a multicopy suppressor of a temperature-sensitive DNA polymerase-alpha mutant was isolated. This gene, named cds1+ (checking DNA synthesis), encodes a typical protein kinase. Here we report that this protein kinase is a key component of the DNA replication-monitoring S/G2 checkpoint system. Our data suggest that its primary role is to monitor DNA synthesis by interacting with DNA polymerase alpha and send a signal to block the onset of mitosis while DNA synthesis is in progress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Checkpoint Kinase 2
  • DNA Polymerase II / metabolism
  • DNA Replication / physiology
  • DNA, Fungal / biosynthesis
  • Hydroxyurea / pharmacology
  • Mitosis / physiology*
  • Molecular Sequence Data
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein-Serine-Threonine Kinases*
  • S Phase / physiology*
  • Schizosaccharomyces / drug effects
  • Schizosaccharomyces / enzymology*
  • Schizosaccharomyces / radiation effects
  • Schizosaccharomyces pombe Proteins
  • Sequence Homology, Amino Acid
  • Ultraviolet Rays


  • DNA, Fungal
  • Schizosaccharomyces pombe Proteins
  • Protein Kinases
  • Checkpoint Kinase 2
  • Cds1 protein, S pombe
  • Protein-Serine-Threonine Kinases
  • DNA Polymerase II
  • Hydroxyurea

Associated data

  • GENBANK/X85040