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PCNA招募了凝聚力加载器Scc2,以确保姐妹染色体凝聚力

Ivan Psakhye¹, Ryotaro Kawasumi^2,3, Takuya Abe³

¹IFOM ETS, the AIRC Institute of Molecular Oncology, Milan, Italy. ivan.psakhye@ifom.eu.

Nature structural & molecular biology

|August 17, 2023

概括

姐妹染色体凝聚力依赖于DNA复制过程中的凝聚力负载. 这项研究揭示了增殖细胞核抗原 (PCNA) 直接招募凝聚素加载器Scc2,这是产生凝聚力的关键步骤.

科学领域:

分子生物学分子生物学
细胞生物学细胞生物学
遗传学是一个遗传学.

背景情况:

姐妹染色体凝聚力对于细胞分裂期间精确的染色体分离至关重要.
凝聚综合体通过依赖复制的途径建立这种凝聚力.
在新复制的DNA上重新加载凝聚素是必不可少的,但在机理上不清楚.

研究的目的:

为了阐明DNA复制过程中新的凝聚力负载的机制.
研究增殖细胞核抗原 (PCNA) 在凝聚力负载中的作用.
为了确定已识别的机制是否在物种中得到保护.

主要方法:

使用酵母遗传学研究了蛋白质与蛋白质的相互作用.
使用了缺乏Scc2-PCNA相互作用的突变物.
检查了结合复杂体突变的凝聚力缺陷.
在脊椎动物细胞模型中证实了这一发现.

主要成果:

证明PCNA通过其PCNA相互作用蛋白 (PIP) 基因物理地招募酵母凝聚载体Scc2.
表明受损的Scc2-PCNA结合导致凝聚力缺陷,特别是当凝聚素转换途径也受到损害时.
证实了NIPBL (人类Scc2) 招募到PCNA在脊椎动物细胞中的凝聚力生成中的保留作用.

结论:

在DNA复制过程中,PCNA作为凝聚力加载器Scc2的直接招募者.
这种相互作用对于通过de novo加载途径建立姐妹染色体凝聚力至关重要.
通过PCNA介导的凝聚力加载者的招募是对基因组稳定性至关重要的进化保守机制.

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