Aurora B prevents chromosome arm separation defects by promoting telomere dispersion and disjunction.
Bottom Line: Dispersion is promoted by the dissociation of Swi6/HP1 and cohesin Rad21 from telomeres, whereas disjunction occurs at anaphase after the phosphorylation of condensin subunit Cnd2.Strikingly, we demonstrate that deletion of Ccq1, a telomeric shelterin component, rescued cell death after Aurora inhibition by promoting the loading of condensin on chromosome arms.Our findings reveal an essential role for telomeres in chromosome arm segregation.
Affiliation: Laboratoire de biologie cellulaire et moléculaire du contrôle de la prolifération, Université de Toulouse, F-31062 Toulouse, France Centre National de la Recherche Scientifique, LBCMCP-UMR5088, F-31062 Toulouse, France.Show MeSH
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Mentions: Chromosome end protection in S. pombe is similar to that seen in mammals and a recent study has identified several proteins including Pot1 or Ccq1 that form the shelterin complex (Miyoshi et al., 2008). Ccq1 is the S. pombe–specific component of this complex and is required for telomerase recruitment (Moser et al., 2011; Yamazaki et al., 2012). Ccq1 also participates in the telomeric recruitment of a multi-enzyme complex (termed SHREC) that mediates heterochromatic transcriptional gene silencing (Sugiyama et al., 2007). The dissociation of shelterin components from telomeres during mitosis was previously demonstrated using chromatin immunoprecipitation (Chang et al., 2013). Our study provides the timing for this dissociation with respect to chromosome segregation and telomere dispersion. It also suggests that Aurora controls the dissociation of Pot1 or Ccq1 at the metaphase-to-anaphase transition (Fig. 9).
Affiliation: Laboratoire de biologie cellulaire et moléculaire du contrôle de la prolifération, Université de Toulouse, F-31062 Toulouse, France Centre National de la Recherche Scientifique, LBCMCP-UMR5088, F-31062 Toulouse, France.