GSE196149
Condensin positioning at telomeres by shelterin proteins drives sister-telomere disjunction in anaphase
The localization of condensin along chromosomes is crucial for their accurate segregation in anaphase. Condensin is enriched at telomeres but how and for what purpose had remained elusive. Here we show that fission yeast condensin accumulates at telomere repeats through the balancing acts of Taz1, a core component of the shelterin complex that ensures telomeric functions, and Mit1, a nucleosome-remodeler associated with shelterin. We further show that condensin takes part in sister-telomere separation in anaphase, and that this event can be uncoupled from the prior separation of chromosomes arms, implying a telomere-specific separation mechanism. Consistent with a cis-acting process, increasing or decreasing condensin occupancy specifically at telomeres modifies accordingly the efficiency of their separation in anaphase. Genetic evidence suggests that condensin promotes sister-telomere separation by counteracting cohesin. Thus, our results reveal a shelterin-based mechanism that enriches condensin at telomeres to drive in cis their separation during mitosis. Overall design: Condensin localisation and chromatin loop formation in fission yeast cells arrested in metaphase. (1) samples for calibrated ChIP-seq of fission yeast Cnd2-GFP in WT, cut14-208, cut3-477 or mit1D mutant cells arrested in metaphase, with 2 technical and biological replicates. (2) samples for Hi-C-seq in WT or cut14-208  fission yeast cells arrested in metaphase, with 2 technical and biological replicates.