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咖啡因通过损害酶IV/XRCC4功能来抑制非同类末端连接
Susmita Kumari1, Divya Sathees1,2, Prashant Kumar Rai3
1Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
Nucleic acids research
|March 3, 2026
概括
咖啡因通过直接与XRCC4结合并破坏其复合体与DNA结合酶IV的作用来抑制非同类末端结合 (NHEJ),这是一个关键的DNA修复途径. 这导致未修复的DNA双链断裂和细胞存活率降低.
科学领域:
- 分子生物学分子生物学
- DNA 修复机制的修复机制
- 细胞生物学 细胞生物学
背景情况:
- DNA双链断裂 (DSB) 是通过同源重组 (HR) 或非同源末端连接 (NHEJ) 修复的关键DNA损伤.
- 众所周知,咖啡因可以抑制HR,但其对NHEJ的影响尚不清楚.
研究的目的:
- 研究咖啡因对非同类末端结合 (NHEJ) DNA 修复的影响.
- 阐明咖啡因影响NHEJ的分子机制.
主要方法:
- 生物化学和细胞分析被用来评估NHEJ抑制.
- 在 silico 中,生物物理和生物化学分析被用来确定咖啡因与修复蛋白的相互作用.
- 进行了免疫光,彗星试验,TUNEL试验和克隆基因生存试验.
主要成果:
- 咖啡因以度依赖的方式抑制NHEJ,导致DSB增加和修复减少.
- 咖啡因直接与XRCC4结合,破坏其与DNA结合酶IV的相互作用,并抑制DNA末端的结合.
- 一个特定的XRCC4 (T133A) 突变减少了咖啡因结合,并部分恢复了NHEJ.
- 咖啡因治疗降低了细胞存活率,特别是在与酶IV缺乏细胞相比的野生类型细胞中.
结论:
- 咖啡因通过直接抑制DNA结合酶IV/XRCC4复合体来抑制NHEJ.
- 这种抑制机制有助于增加DNA损伤,并在咖啡因暴露下降低细胞活力.
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