Sae2集成CDK和检查点酸化,以协调MRX裂变与检查点衰减
Erika Casari1, Marco Gnugnoli1, Paolo Pizzul1
1Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Milano, Italy.
Communications biology
|December 24, 2025
概括
酵母 Sae2 酸化由 Mec1/Tel1 激酶抑制 Rad53 DNA 损伤反应. 化T279还促进了DNA修复,特别是在介质双链断裂.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 酵母Sae2蛋白在DNA损伤反应中具有双重作用.
- 它抑制了Rad53的激活,并有助于MRX复合体对DNA的最终处理.
研究的目的:
- 阐明Sae2在DNA损伤反应中的调节机制.
- 研究SAE2酸化在T90和T279在调节Rad53和DNA修复中的作用.
主要方法:
- 基于AlphaFold3的结构建模.
- 位点定向的突变发生和相学分析.
- 对DNA损伤检查点激活和DNA修复过程的分析.
主要成果:
- 在T90或T279中对Sae2的Mec1/Tel1依赖酸化抑制了Rad9-Rad53相互作用和Rad53激活.
- 非酸化的Sae2突变 (T90A T279A) 显示持续的Rad53激活.
- 相仿Sae2变种 (T90E,T279E) 恢复正常的检查点不活化.
- 化SAE2 (T90/T279) 和Rad53 (R70) 之间的静电相互作用对于调节至关重要.
- T279酸化,与CDK依赖的S267酸化一起,促进MRX介导的毛分辨率和介质DSB处理.
- 一种Sae2 T279E突变物在tel1Δ细胞中部分挽救了针头裂缺陷和DNA损伤敏感性.
结论:
- 在T90/T279的Sae2酸化是抑制Rad53DNA损伤反应的关键机制.
- 泰尔1激酶主要通过Sae2 T279酸化促进MRX活性.
- Sae2 T279酸化对于处理介质双链断裂和解决DNA发针结构至关重要.
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