Centromeres become unstuck without heterochromatin.
In most if not all eukaryotes, sister-chromatid cohesion, which is mediated by the chromosomal complex Cohesin, is destroyed by proteolysis at the transition from metaphase to anaphase. In metazoans, Cohesin is removed from chromosomes in two steps, and the centromere and its associated pericentric heterochromatin constitute the last point of linkage between sister chromatids at metaphase. Mechanistic insight is now emerging on the way in which cells distinguish cohesion at the centromere from cohesion along chromosome arms. We discuss recent advances in our understanding of the role of centromeric heterochromatin in sister-chromatid cohesion and propose a causal relationship between this specialized type of chromatin and the removal by proteolysis of Cohesins that are associated with it.
Bernard
Pascal
P
Institut de Biochimie et Génétique Cellulaires, CNRS UMR 5095, 1 rue Camille Saint Saens, 33077 Cedex, Bordeaux, France.
Allshire
Robin
R
D000818:Animals; D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins; D002503:Centromere / Q000378:metabolism*; D002842:Chromatids / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D020090:Chromosome Segregation; D005656:Fungal Proteins / Q000378:metabolism; D006570:Heterochromatin / Q000378:metabolism*; D006801:Humans; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000378:metabolism*; D000097722:Cohesins
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D005656:Fungal Proteins; D006570:Heterochromatin; D009687:Nuclear Proteins; D000097722:Cohesins