1. Physical Proximity of Sister Chromatids Promotes Top2-Dependent Intertwining
- Author
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Sen, N, Leonard, J, Torres, R, Garcia-Luis, J, Palou-Marin, G, Aragon Alcaide, L, and Wellcome Trust
- Subjects
DNA Replication ,Biochemistry & Molecular Biology ,chromosome segregation ,PROTEIN ,cohesin ,Gene Expression ,Saccharomyces cerevisiae ,Chromatids ,SACCHAROMYCES-CEREVISIAE ,TOPOISOMERASE-II ,TOPOLOGY ,COHESION ,DNA TOPOISOMERASES ,DNA, Fungal ,Molecular Biology ,11 Medical and Health Sciences ,Adenosine Triphosphatases ,Science & Technology ,DECATENATION ,condensin ,IN-VITRO ,Cell Biology ,06 Biological Sciences ,catenation ,DNA-Binding Proteins ,G2 Phase Cell Cycle Checkpoints ,DNA Topoisomerases, Type II ,MITOTIC CHROMOSOME CONDENSATION ,SCI ,MITOSIS ,Multiprotein Complexes ,Top2 (Topoisomerase 2) ,Chromosomes, Fungal ,Anaphase ,Life Sciences & Biomedicine ,Developmental Biology - Abstract
Sister chromatid intertwines (SCIs), or catenanes, are topological links between replicated chromatids that interfere with chromosome segregation. The forma- tion of SCIs is thought to be a consequence of fork swiveling during DNA replication, and their removal is thought to occur because of the intrinsic feature of type II topoisomerases (Top2) to simplify DNA topology. Here, we report that SCIs are also formed independently of DNA replication during G 2 /M by Top2-dependent concatenation of cohesed chroma- tids due to their physical proximity. We demonstrate that, in contrast to G 2 /M, Top2 removes SCIs from co- hesedchromatidsattheanaphaseonset.Importantly, SCI removal in anaphase requires condensin and co- incides with the hyperactivation of condensin DNA supercoiling activity. This is consistent with the long- standing proposal that condensin provides a bias in Top2functiontowarddecatenation.Acomprehensive model for the formation and resolution of toxic SCI entanglements on eukaryotic genomes is proposed.
- Published
- 2016
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