Cut2 proteolysis required for sister-chromatid seperation in fission yeast

Nature. 1996 May 30;381(6581):438-41. doi: 10.1038/381438a0.


Although mitotic cyclins are well-known substrates for ubiquitin-mediated proteolysis at the metaphase-anaphase transition, their degradation is not essential for separation of sister chromatids; several lines of evidence suggest that proteolysis of other protein(s) is required, however. Here we report the anaphase-specific proteolysis of the Schizosaccharomyces pombe Cut2 protein, which is essential for sister-chromatid separation. Cut2 is located in the nucleus, where it is concentrated along the short metaphase spindle. The rapid degradation of Cut2 at anaphase requires its amino-terminal region and the activity of Cut9 (ref. 14), a component of the 20S cyclosome/anaphase-promoting complex (APC), which is necessary for cyclin destruction. Expression of non-degradable Cut2 blocks sister-chromatid separation but not cell-cycle progression. This defect can be overcome by grafting the N terminus of cyclin B onto the truncated Cut2, demonstrating that the regulated proteolysis of Cut2 is essential for sister-chromatid separation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Division / physiology
  • Cell Nucleus / physiology
  • Chromatids*
  • Fungal Proteins / metabolism*
  • Molecular Sequence Data
  • Recombinant Proteins / metabolism
  • Schizosaccharomyces / cytology
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces / metabolism


  • Fungal Proteins
  • Recombinant Proteins