MutSβ-MutLβ-FANCJ轴介导在配转录G4/R循环中分叉停滞后重启DNA复制
Esin Isik1, Kaustubh Shukla2, Michaela Pospisilova3,4
1Institute of Molecular Cancer Research, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
Science advances
|February 7, 2024
概括
DNA复制分叉在转录复制冲突 (TRC) 中停滞,形成G-四重复/R-循环. MutSβ,MutLβ和FANCJ解决了这些结构,使复制重启.
科学领域:
- 分子生物学分子生物学
- 复制DNA复制DNA复制DNA复制
- 修复DNA修复DNA的修复
背景情况:
- 转录复制冲突 (TRC) 会导致复制分叉停滞.
- 协转录RNA:由G-四复合体 (G4s) 稳定的DNA混合体 (R-循环) 在TRC过程中导致分叉停滞.
- 删除G4/R循环以允许在停滞后重新启动复制的机制尚未完全理解.
研究的目的:
- 阐明在TRC过程中在停滞的复制叉中负责解决G4/R循环的分子机制.
- 确定参与TRC地点重新启动DNA复制的关键蛋白质.
主要方法:
- 研究了不匹配修复蛋白质,特别是MutSβ和MutLβ (MLH1-PMS1) 和酶FANCJ在人类细胞中TRC部位的DNA修复中的作用.
- 在复制重启的背景下,评估了G4结合和酶活动的功能依赖.
- 研究了MutSβ,MutLβ和FANCJ之间的相互作用,以及它们对G4结构的招募.
主要成果:
- MutSβ,MutLβ和FANCJ对于MUS81启动的DNA复制在TRC地点的重新启动至关重要.
- MutSβ的G4结合活性,FANCJ的螺旋酶活性以及FANCJ与MLH1的相互作用对这一过程至关重要.
- MutSβ,MutLβ和MLH1-FANCJ复合体合作,将FANCJ招募到G4结构中.
结论:
- MutSβ,MutLβ和FANCJ集体地起作用,以解决阻碍TRC位点复制进展的G4/R循环.
- 这种协调的行动促进了DNA复制的重新启动,保持了基因组的稳定性.
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