Multiple determinants and consequences of cohesion fatigue in mammalian cells.
Multiple determinants and consequences of cohesion fatigue in mammalian cells.
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DOI：
10.1091/mbc.e18-05-0315
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发表时间：
2018-08-01
影响因子：
3.3
通讯作者：
Gorbsky GJ
中科院分区：
文献类型：
--
作者：
Sapkota H;Wasiak E;Daum JR;Gorbsky GJ
有丝分裂纺锤体完整的细胞在中期延迟时发生内聚疲劳，此时姐妹染色单体异步分离，而细胞仍处于有丝分裂状态。凝聚疲劳需要姐妹染色单体凝聚力的释放。然而，在凝聚疲劳过程中破坏姐妹染色单体凝聚力的途径仍然未知。使用适度的盐缓冲液，以消除松散结合的染色质粘蛋白，我们表明，“粘性”粘蛋白不释放在染色单体分离过程中的凝聚力疲劳。使用受调控的蛋白质异源二聚化系统锁定不同的粘附素环接口在特定的时间在有丝分裂中，我们表明，Wapl介导的粘附素释放途径是不需要的凝聚力疲劳。通过操纵微管的稳定性和凝聚力复合物的完整性在细胞系中具有不同的敏感性，凝聚力疲劳，我们表明，凝聚力疲劳率反映了纺锤体拉力和耐分离染色单体间凝聚力之间的动态平衡。最后，虽然大规模分离的染色单体的凝聚力疲劳可能会产生不可活的细胞后代，我们发现，短中期延迟，导致部分染色单体分离，易使细胞染色体误分离。因此，一条或几条染色体的完全分离和/或姐妹染色单体的部分分离可能是染色体不稳定性的一个未被认识但常见的来源，其使癌症中的恶性细胞的进化永久化。
Cells delayed in metaphase with intact mitotic spindles undergo cohesion fatigue, where sister chromatids separate asynchronously, while cells remain in mitosis. Cohesion fatigue requires release of sister chromatid cohesion. However, the pathways that breach sister chromatid cohesion during cohesion fatigue remain unknown. Using moderate-salt buffers to remove loosely bound chromatin cohesin, we show that “cohesive” cohesin is not released during chromatid separation during cohesion fatigue. Using a regulated protein heterodimerization system to lock different cohesin ring interfaces at specific times in mitosis, we show that the Wapl-mediated pathway of cohesin release is not required for cohesion fatigue. By manipulating microtubule stability and cohesin complex integrity in cell lines with varying sensitivity to cohesion fatigue, we show that rates of cohesion fatigue reflect a dynamic balance between spindle pulling forces and resistance to separation by interchromatid cohesion. Finally, while massive separation of chromatids in cohesion fatigue likely produces inviable cell progeny, we find that short metaphase delays, leading to partial chromatid separation, predispose cells to chromosome missegregation. Thus, complete separation of one or a few chromosomes and/or partial separation of sister chromatids may be an unrecognized but common source of chromosome instability that perpetuates the evolution of malignant cells in cancer.