In eukaryotes, the process of sister chromatid cohesion holds the two sister chromatids (the replicated chromosomes) together from DNA replication to the onset of chromosome segregation. Cohesion is mediated by cohesin, a four-subunit SMC (structural maintenance of chromosome) complex. Cohesin and cohesion are required for proper chromosome segregation, DNA repair, and gene expression. To carry out these functions, cohesion is regulated by elaborate mechanisms involving a growing list of cohesin auxiliary factors. These factors control the timing and position of cohesin binding to chromatin, activate chromatin-bound cohesin to become cohesive, and orchestrate the orderly dissolution of cohesion. The 45-nm ringlike architecture of soluble cohesin is compatible with dramatically different mechanisms for both chromatin binding and cohesion generation. Solving the mechanism of cohesion and its complex regulation presents significant challenges but offers the potential to provide important insights into higher-order chromosome organization and chromosome biology.

中文翻译：

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姐妹染色单体内聚力：一个简单的概念与复杂的现实。


在真核生物中，从 DNA 复制到染色体分离开始，姐妹染色单体凝聚过程将两个姐妹染色单体（复制的染色体）保持在一起。凝聚力由粘连蛋白介导，粘连蛋白是一种四亚基 SMC（染色体结构维持）复合物。正确的染色体分离、DNA 修复和基因表达需要粘连蛋白和内聚力。为了执行这些功能，内聚力受到复杂机制的调节，涉及越来越多的内聚素辅助因子。这些因素控制着粘连蛋白与染色质结合的时间和位置，激活染色质结合的粘连蛋白变得具有粘性，并协调粘连的有序溶解。可溶性粘连蛋白的 45 nm 环状结构与染色质结合和粘连生成的截然不同的机制兼容。解决内聚机制及其复杂的调控提出了重大挑战，但有可能为高阶染色体组织和染色体生物学提供重要见解。