Shugoshin promotes sister kinetochore biorientation in Saccharomyces cerevisiae

Mol Biol Cell. 2008 Mar;19(3):1199-209. doi: 10.1091/mbc.e07-06-0584. Epub 2007 Dec 19.

Abstract

Chromosome segregation must be executed accurately during both mitotic and meiotic cell divisions. Sgo1 plays a key role in ensuring faithful chromosome segregation in at least two ways. During meiosis this protein regulates the removal of cohesins, the proteins that hold sister chromatids together, from chromosomes. During mitosis, Sgo1 is required for sensing the absence of tension caused by sister kinetochores not being attached to microtubules emanating from opposite poles. Here we describe a differential requirement for Sgo1 in the segregation of homologous chromosomes and sister chromatids. Sgo1 plays only a minor role in segregating homologous chromosomes at meiosis I. In contrast, Sgo1 is important to bias sister kinetochores toward biorientation. We suggest that Sgo1 acts at sister kinetochores to promote their biorientation.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaphase-Promoting Complex-Cyclosome
  • Chromosome Segregation
  • Chromosomes, Fungal / metabolism
  • Enzyme Activation
  • Gene Deletion
  • Kinetochores / metabolism*
  • Meiosis
  • Metaphase
  • Microtubules / metabolism
  • Nuclear Proteins / metabolism*
  • Recombination, Genetic / genetics
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Spindle Apparatus / metabolism
  • Ubiquitin-Protein Ligase Complexes / metabolism

Substances

  • Nuclear Proteins
  • Saccharomyces cerevisiae Proteins
  • Sgo1 protein, S cerevisiae
  • Ubiquitin-Protein Ligase Complexes
  • Anaphase-Promoting Complex-Cyclosome