ATR 调节脆弱地点的稳定性
Anne M Casper1, Paul Nghiem, Martin F Arlt
1Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA.
Cell
|January 16, 2003
概括
常见的脆弱部位,易于瘤中断裂,由ATR激酶稳定. ATR 缺乏导致脆弱部位的表达,揭示了它们在未复制的DNA区域和停滞的复制分叉中的作用.
科学领域:
- 遗传学 是一个遗传学.
- 分子生物学分子生物学
- 癌症生物学 癌症生物学
背景情况:
- 常见的脆弱部位 (CFS) 是染色体区域,在复制压力下容易发生差距和断裂.
- 经常在各种人体瘤中观察到CFS的不稳定性,包括删除和重新排列.
- 导致CFS表达的精确分子机制及其与癌症中的基因组不稳定性的联系在很大程度上是未知的.
研究的目的:
- 阐明复制检查点激酶,特别是ATR和ATM在维持脆弱部位稳定的作用.
- 调查ATR或ATM是否对于防止DNA复制应激期间脆弱部位的表达至关重要.
- 根据ATR复制检查点的功能,提出一个脆弱站点形成模型.
主要方法:
- 使用基于细胞的测试来评估在部分DNA复制抑制条件下脆弱部位的表达.
- 采用遗传方法,在哺乳动物细胞中消耗或禁用ATR和ATM激酶.
- 分析元相染色体,以检测存在间隙,断裂和重排,这些都是脆弱部位表达的迹象.
主要成果:
- 该研究表明,ATR激酶,但不是ATM,对于维持常见脆弱部位的稳定性至关重要.
- 缺少ATR导致脆弱部位的特征表达,即使没有外部复制抑制剂.
- 这些发现表明,脆弱部位代表了未复制的染色体段,其中复制分叉已经逃脱了ATR介导检查点控制.
结论:
- 脆弱部位的不稳定性严重依赖于ATR介导的复制检查点.
- 由于ATR缺乏,脆弱部位会自发表达,这表明它们本质上是不稳定的区域,容易陷入停滞.
- 拟议的模型假定脆弱地点是未复制的区域,由陷入停滞的复制分叉产生的,这些分叉可以逃避ATR监测,这对癌症的发展和基因组稳定性有重大影响.
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