在DNA损伤反应中,需要对尼日梅根断裂综合征蛋白的ATM酸化
X Wu1, V Ranganathan, D S Weisman
1Dana Farber Cancer Institute, Boston, Massachusetts 02115, USA.
Nature
|June 6, 2000
概括
尼米根断裂综合征 (NBS) 通过ATM激酶的蛋白质酸化对DNA损伤反应至关重要. 这种ATM介导的NBS酸化对于暴露于马辐射后的人类细胞生存至关重要.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 尼米根断裂综合征 (NBS) 呈现出极度的辐射敏感性,染色体不稳定性和癌症.
- NBS与阿塔克西亚特朗吉克塔西亚突变 (ATM) 疾病有共同的表型,这表明有共同的DNA损伤反应途径.
- ATM是一种由DNA损伤激活的蛋白激酶.
研究的目的:
- 为了研究NBS蛋白酸化对DNA损伤的反应中的作用.
- 为了确定ATM激酶是否酸化NBS蛋白.
- 阐明ATM依赖的NBS酸化在细胞对辐射反应中的功能意义.
主要方法:
- 在暴露于马辐射,紫外线和氧尿素时,研究了NBS蛋白质酸化.
- 在正常和ATM缺陷细胞中比较NBS酸化水平.
- 采用了体外激酶试验来识别NBS上的ATM-化血清残留物.
- 生成的NBS突变体与非活化的ATM依赖酸化位点.
- 评估了NBS酸化状态对玛辐射后克隆基因生存的影响.
主要成果:
- 作为对玛辐射,紫外线和氧尿素的反应,NBS蛋白质具有特定的酸化.
- 在ATM缺乏细胞中,马辐射诱导的NBS酸化显著减少.
- 在体外,ATM激酶直接在特定的血清残留物 (S343,S397,S615) 上酸化NBS蛋白.
- 突变这些依赖ATM的部位会损害NBS的酸化,并减少玛辐射后的细胞存活率.
结论:
- 根据ATM,NBS的酸化对细胞对DNA损伤的反应至关重要,尤其是玛辐射.
- 这种酸化事件对于维持基因组稳定性和细胞在对基因毒性压力的反应中存活至关重要.
- 这些发现突出了涉及NBS和ATM的DNA修复途径的关键监管机制.
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