Cohesin is a DNA translocase that is instrumental in the folding of the genome into chromatin loops, with functional consequences on DNA-related processes. Chromatin loop length and organization likely depend on cohesin processivity, translocation rate and stability on DNA. Here, we investigate and provide a comprehensive overview of the roles of various cohesin regulators in tuning chromatin loop expansion in budding yeast Saccharomyces cerevisiae. We demonstrate that Scc2, which stimulates cohesin ATPase activity, is also essential for cohesin translocation, driving loop expansion in vivo. Smc3 acetylation during the S phase counteracts this activity through the stabilization of Pds5, which finely tunes the size and stability of loops in G2.

Cohesin 是一种 DNA 转位酶，有助于将基因组折叠成染色质环，并对 DNA 相关过程产生功能性影响。染色质环长度和组织可能取决于黏连蛋白的合成能力、易位率和 DNA 的稳定性。在这里，我们调查并全面概述了各种黏连蛋白调节剂在调节出芽酵母酿酒酵母中染色质环扩展的作用。我们证明 Scc2 可刺激内聚素 ATP 酶活性，对于内聚素易位、驱动体内循环扩展也是必不可少的。S 期 Smc3 乙酰化通过稳定 Pds5 来抵消这种活性，从而微调 G2 中环的大小和稳定性。