Displacement and re-accumulation of centromeric cohesin during transient pre-anaphase centromere splitting

Chromosoma. 2007 Dec;116(6):531-44. doi: 10.1007/s00412-007-0118-4. Epub 2007 Sep 1.

Abstract

The ring-shaped cohesin complex links sister chromatids until their timely segregation during mitosis. Cohesin is enriched at centromeres where it provides the cohesive counterforce to bipolar tension produced by the mitotic spindle. As a consequence of spindle tension, centromeric sequences transiently split in pre-anaphase cells, in some organisms up to several micrometers. This 'centromere breathing' presents a paradox, how sister sequences separate where cohesin is most enriched. We now show that in the budding yeast Saccharomyces cerevisiae, cohesin binding diminishes over centromeric sequences that split during breathing. We see no evidence for cohesin translocation to surrounding sequences, suggesting that cohesin is removed from centromeres during breathing. Two pools of cohesin can be distinguished. Cohesin loaded before DNA replication, which has established sister chromatid cohesion, disappears during breathing. In contrast, cohesin loaded after DNA replication is partly retained. As sister centromeres re-associate after transient separation, cohesin is reloaded in a manner independent of the canonical cohesin loader Scc2/Scc4. Efficient centromere re-association requires the cohesion establishment factor Eco1, suggesting that re-establishment of sister chromatid cohesion contributes to the dynamic behaviour of centromeres in mitosis. These findings provide new insights into cohesin behaviour at centromeres.

Publication types

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

MeSH terms

  • Anaphase / genetics*
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Centromere / genetics
  • Centromere / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Cohesins
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism

Substances

  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • Nuclear Proteins
  • Saccharomyces cerevisiae Proteins