在G1中同源重组的激活保持了中心体完整性
Duygu Yilmaz1,2,3,4, Audrey Furst1,2,3,4, Karen Meaburn5
1Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.
Nature
|December 2, 2021
概括
通过招募DNA修复机器,即使没有姐妹染色体,中粒体也保持了细胞分裂的完整性. 这种涉及CENP-A和H3K4me2的过程可以防止基因组不稳定.
科学领域:
- 细胞生物学
- 遗传学
- 分子生物学
背景情况:
- 对于精确的染色体分离而言,中心整体性至关重要.
- 中介质具有独特的染色质结构,对其维护至关重要.
- 中介质容易发生DNA断裂和重组,但DNA损伤修复的机制尚不清楚.
研究的目的:
- 调查细胞周期G1阶段DNA损伤后如何保持中粒体完整性.
- 阐明在G1中中心基DNA断裂时许可同源重组的分子机制.
主要方法:
- 研究了G1阶段细胞中中间体的DNA断裂修复.
- 分析了CENP-A,HJURP和H3K4me2在同源重组许可中的作用.
- 研究了CENP-A/HJURP和USP11之间的相互作用,以及RAD51-BRCA1-BRCA2复合物的形成.
- 评估了抑制G1同类重组的后果.
主要成果:
- 尽管缺少姐妹染色体,但G1中的中心性DNA断裂会招募同类的重组机制.
- 通过促进DNA切除和转录,CENP-A,HJURP和H3K4me2在G1中促进同源重组许可.
- 通过USP11与CENP-A/HJURP的相互作用,可以形成RAD51复合体,并将其注入中位素.
- 在G1中抑制同类重组会导致中心体的不稳定性和转位.
结论:
- 在整个细胞周期中,同源重组在中心断裂时得到许可.
- 这种许可可以防止突变性修复途径,并保持中心体的完整性.
- 这些发现揭示了维护基因组稳定的新机制.
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