由于DNA损伤引起的p53酸化减轻了MDM2的抑制作用
1Department of Biological Sciences, Columbia University, New York, New York 10027, USA.
Cell
|November 18, 1997
概括
DNA 损伤会通过酶15的酸化触发p53的激活,从而减少它与MDM2.2的相互作用. 这种酸化,特别是由DNA依赖蛋白激酶 (DNA-PK) 进行的酸化,增强了p53的活性.
科学领域:
- 分子生物学分子生物学
- 细胞信号传输 细胞信号传输
- 癌症研究 癌症研究
背景情况:
- 破坏DNA的药物通过转录后机制激活瘤抑制剂p53.
- 对于p53调节而言,p53与其负调节器MDM2 (小鼠双分钟2) 的相互作用至关重要.
- 连接DNA损伤与p53激活的精确分子事件仍然不完全理解.
研究的目的:
- 阐明转录后机制,通过这些机制DNA损伤信号到p53.
- 研究p53酸化在调节其与MDM2.2相互作用中的作用.
- 确定p53酸化对p53依赖的交换激活的功能影响.
主要方法:
- 西方涂抹检测p53酸化在血清15.
- 同免疫沉降测试以评估p53-MDM2相互作用在体外和体内.
- 在体外激酶试验中使用纯化的DNA依赖蛋白激酶 (DNA-PK) 和p53.
- 报告员测试以测量p53依赖的交易活动.
主要成果:
- 在DNA损伤后,人类p53在血清15的酸化发生.
- 化15级血清减少了p53和MDM2.2之间的体内和体外相互作用.
- 通过DNA-PK对p53在15和37序列中的酸化会损害MDM2抑制p53交换活化的能力.
- 这些效应归因于p53.3中酸化诱导的形状变化.
结论:
- 酸化p53在15序列是关键的转录后事件,将DNA损伤与p53激活联系起来.
- 这种酸化事件破坏了p53-MDM2相互作用,缓解了MDM2介导的p53.3抑制.
- DNA-PK和潜在的其他激酶调解p53酸化,为p53诱导提供了响应DNA损伤的机制.
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