在DNA跨链跨链修复过程中,ATM促进了反向叉处理
Maria Altshuller1, Victoria A MacKrell1, Jasmine Tzeng1
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA.
bioRxiv : the preprint server for biology
|November 24, 2025
概括
这项研究揭示了DNA链间交叉链 (ICL) 修复如何使用分叉逆转和ATM激酶激活. 蛋白酸酶2A (PP2A) 平衡了这一过程,以防止在复制过程中损害DNA.
科学领域:
- DNA 修复机制的修复机制
- 细胞对DNA损伤的反应
- 分子细胞生物学分子细胞生物学
背景情况:
- 复制合DNA跨链交叉连接 (ICL) 修复涉及至关重要的分叉重塑事件.
- 在ICL修复过程中扭转和恢复叉的规则仍然不太了解.
- 芬科尼贫血 (FA) 途径是解决ICLs的核心.
研究的目的:
- 通过使用无细胞Xenopus蛋提取物,通过FA途径研究ICL修复期间的叉动力学.
- 阐明在ICL修复过程中控制逆叉处理的监管机制.
主要方法:
- 利用无细胞的Xenopus蛋提取物来模拟ICL修复.
- 调查了在叉子逆转中阿塔克西亚特朗吉克塔西亚突变 (ATM) 激酶的作用.
- 评估了EXO1和DNA2核酶在逆叉切除中的功能.
- 研究了蛋白酸酶2A (PP2A) 抑制对ATM信号和叉子处理的影响.
主要成果:
- ATM 激酶激活与叉子逆转并发,并促进逆转叉子中间体的切除.
- EXO1和DNA2核酶协调切除反向叉,EXO1启动,DNA2进行进一步的切除.
- 抑制PP2A导致ATM过度激活,过度逆叉切除和异常的末端连接产品.
- 反向叉被确定为ATM激活的基板.
结论:
- 一个涉及ATM和PP2A的光调节电路控制了ICL修复期间的反向叉处理.
- 这个电路确保了反向叉的受控切除,防止异常的DNA修复结果.
- 这些发现为ICL修复过程中DNA复制分叉动态的调节提供了新的见解.
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