ALBA 蛋白复合物读取基因 R 环以维持基因组稳定性。
ALBA protein complex reads genic R-loops to maintain genome stability in .
机构信息
State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, China.
Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
出版信息
Sci Adv. 2019 May 15;5(5):eaav9040. doi: 10.1126/sciadv.aav9040. eCollection 2019 May.
The R-loop, composed of a DNA-RNA hybrid and the displaced single-stranded DNA, regulates diverse cellular processes. However, how cellular R-loops are recognized remains poorly understood. Here, we report the discovery of the evolutionally conserved ALBA proteins (AtALBA1 and AtALBA2) functioning as the genic R-loop readers in . While AtALBA1 binds to the DNA-RNA hybrid, AtALBA2 associates with single-stranded DNA in the R-loops in vitro. In vivo, these two proteins interact and colocalize in the nucleus, where they preferentially bind to genic regions with active epigenetic marks in an R-loop-dependent manner. Depletion of AtALBA1 or AtALBA2 results in hypersensitivity of plants to DNA damaging agents. The formation of DNA breaks in mutants originates from unprotected R-loops. Our results reveal that the AtALBA1 and AtALBA2 protein complex is the genic R-loop reader crucial for genome stability in .
R 环由 DNA-RNA 杂交体和移位的单链 DNA 组成，调节多种细胞过程。然而，细胞 R 环如何被识别仍知之甚少。在这里，我们报告了进化上保守的 ALBA 蛋白（AtALBA1 和 AtALBA2）的发现，它们作为. 的基因 R 环阅读器发挥作用。虽然 AtALBA1 与 DNA-RNA 杂交体结合，但 AtALBA2 体外与 R 环中的单链 DNA 结合。在体内，这两种蛋白质相互作用并在核内共定位，在那里它们以 R 环依赖的方式优先与具有活跃表观遗传标记的基因区域结合。AtALBA1 或 AtALBA2 的耗竭会导致植物对 DNA 损伤剂的敏感性增加。在 突变体中 DNA 断裂的形成源自无保护的 R 环。我们的结果表明，AtALBA1 和 AtALBA2 蛋白复合物是基因 R 环阅读器，对 中的基因组稳定性至关重要。
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