Kanke Mai, Tahara Eri, Huis In't Veld Pim J, Nishiyama Tomoko
Division of Biological Science, Graduate School of Science Nagoya University, Nagoya, Japan.
Research Institute of Molecular Pathology, Vienna, Austria.
EMBO J. 2016 Dec 15;35(24):2686-2698. doi: 10.15252/embj.201695756. Epub 2016 Nov 21.
Cohesin is a ring-shaped protein complex that plays a crucial role in sister chromatid cohesion and gene expression. The dynamic association of cohesin with chromatin is essential for these functions. However, the exact nature of cohesin dynamics, particularly cohesin translocation, remains unclear. We evaluated the dynamics of individual cohesin molecules on DNA and found that the cohesin core complex possesses an intrinsic ability to traverse DNA in an adenosine triphosphatase (ATPase)-dependent manner. Translocation ability is suppressed in the presence of Wapl-Pds5 and Sororin; this suppression is alleviated by the acetylation of cohesin and the action of mitotic kinases. In Xenopus laevis egg extracts, cohesin is translocated on unreplicated DNA in an ATPase- and Smc3 acetylation-dependent manner. Cohesin movement changes from bidirectional to unidirectional when cohesin faces DNA replication; otherwise, it is incorporated into replicating DNA without being translocated or is dissociated from replicating DNA This study provides insight into the nature of individual cohesin dynamics and the mechanisms by which cohesin achieves cohesion in different chromatin contexts.
黏连蛋白是一种环状蛋白质复合物,在姐妹染色单体黏连和基因表达中起关键作用。黏连蛋白与染色质的动态关联对于这些功能至关重要。然而,黏连蛋白动态变化的确切性质,尤其是黏连蛋白易位,仍不清楚。我们评估了单个黏连蛋白分子在DNA上的动态变化,发现黏连蛋白核心复合物具有以三磷酸腺苷酶(ATP酶)依赖方式穿越DNA的内在能力。在Wapl - Pds5和Sororin存在时,易位能力受到抑制;黏连蛋白的乙酰化和有丝分裂激酶的作用可减轻这种抑制。在非洲爪蟾卵提取物中,黏连蛋白以ATP酶和Smc3乙酰化依赖方式在未复制的DNA上易位。当黏连蛋白面对DNA复制时,其运动从双向变为单向;否则,它会被整合到复制的DNA中而不发生易位,或者从复制的DNA中解离。本研究深入了解了单个黏连蛋白动态变化的性质以及黏连蛋白在不同染色质环境中实现黏连的机制。