Entrapment of Chromosomes by Condensin Rings Prevents Their Breakage during Cytokinesis
Entrapment of Chromosomes by Condensin Rings Prevents Their Breakage during Cytokinesis
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DOI：
10.1016/j.devcel.2013.10.018
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发表时间：
2013-11-25
影响因子：
11.8
通讯作者：
Haering, Christian H.
中科院分区：
文献类型：
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作者：
Cuyien, Sara;Metz, Jutta;Haering, Christian H.
在有丝分裂和减数分裂期间染色体的成功分离取决于环状凝聚素复合体的作用，但凝聚素如何确保姐妹染色单体的完全分离尚不清楚。我们发现，未能分离染色体臂，这是由于从染色体上的缩合蛋白释放其环结构的蛋白水解裂解，导致DNA损伤检查点依赖性细胞周期停滞。检查点激活是由胞质分裂过程中染色体断裂的形成触发的，尽管存在落后的染色体臂，但胞质分裂仍以正常的时间进行。值得注意的是，在进入后期之前通过化学诱导的二聚化来加强缩合环的重新闭合足以恢复染色体臂的分离。我们认为，拓扑截留染色体臂的凝聚素环，确保他们的间隙从分裂平面，从而避免其断裂过程中胞质分裂。
Successful segregation of chromosomes during mitosis and meiosis depends on the action of the ring-shaped condensin complex, but how condensin ensures the complete disjunction of sister chromatids is unknown. We show that the failure to segregate chromosome arms, which results from condensin release from chromosomes by proteolytic cleavage of its ring structure, leads to a DNA damage checkpoint-dependent cell-cycle arrest. Checkpoint activation is triggered by the formation of chromosome breaks during cytokinesis, which proceeds with normal timing despite the presence of lagging chromosome arms. Remarkably, enforcing condensin ring reclosure by chemically induced dimerization just before entry into anaphase is sufficient to restore chromosome arm segregation. We suggest that topological entrapment of chromosome arms by condensin rings ensures their clearance from the cleavage plane and thereby avoids their breakage during cytokinesis.