Sister-chromatid separation at anaphase onset is promoted by cleavage of the cohesin subunit Scc1
Sister-chromatid separation at anaphase onset is promoted by cleavage of the cohesin subunit Scc1
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DOI：
10.1038/21831
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发表时间：
1999-07-01
期刊：
影响因子：
64.8
通讯作者：
Nasmyth, K
中科院分区：
文献类型：
--
作者：
Uhlmann, F;Lottspeich, F;Nasmyth, K
姐妹染色单体之间的凝聚力是在DNA复制过程中建立的，并依赖于一种称为凝聚素的多蛋白复合物。在有丝分裂过程中，姐妹着丝粒附着在纺锤体上产生的力，如果没有凝聚力的反对，会立即分裂姐妹染色单体。凝聚力是必不可少的染色体排列在中期，但必须取消姐妹分离开始在后期。在芽殖酵母酿酒酵母中，姐妹染色单体凝聚力的丧失依赖于一种称为Esp 1的分离蛋白（分离蛋白），并伴随着凝聚力亚基Scc 1从染色体上解离。在这里，我们表明，Esp1的原因dissociiation的Scc1从染色体刺激其分裂的蛋白水解。描述了一种突变体Scc 1，其对Esp1依赖性切割具有抗性，并且阻断姐妹染色单体分离和Scc 1从染色体上解离。分离蛋白的进化保守性表明，蛋白水解裂解的凝聚蛋白可能是一个通用的机制，触发后期。
Cohesion between sister chromatids is established during DNA replication and depends on a multiprotein complex called cohesin. Attachment of sister kinetochores to the mitotic spindle during mitosis generates forces that would immediately split sister chromatids were it not opposed by cohesion. Cohesion is essential for the alignment of chromosomes in metaphase but must be abolished for sister separation to start during anaphase. In the budding yeast Saccharomyces cerevisiae, loss of sister-chromatid cohesion depends on a separating protein (separin) called Esp 1 and is accompanied by dissociation from the chromosomes of the cohesion subunit Scc1. Here we show that Esp1 causes the dissooiation of Scc1 from chromosomes by stimulating its cleavage by proteolysis. A mutant Scc1 is described that is resistant to Esp1-dependent cleavage and which blocks both sister-chromatid separation and the dissociation of Scc1 from chromosomes. The evolutionary conservation of separins indicates that the proteolytic cleavage of cohesion proteins might be a general mechanism for triggering anaphase.