通过单个ACF复合体进行核细胞重塑的动力学
Timothy R Blosser1, Janet G Yang, Michael D Stone
1Howard Hughes Medical Institute, Massachusetts 02138, USA.
Nature
|December 25, 2009
概括
依赖ATP的染色体重塑器ACF在不同的步骤中沿着DNA移动细胞核,利用ATP进行结合,转位和暂停释放. 这揭示了ACF是一种高度过程性和双向的核细胞转位酶.
科学领域:
- 染色体生物学 染色体生物学
- 基因调节的分子机制
- 原子核的动态 原子核的动态
背景情况:
- 取决于ATP的染色体组装和重塑因子 (ACF) 对于产生有规律的核细胞间隔至关重要,这对于遗传基因沉默至关重要.
- 通过ACF调动核体的确切机制在很大程度上仍未被阐明.
研究的目的:
- 通过ACF使用单分子Förster共振能量转移 (FRET) 来研究核细胞重塑的实时动态和中间体.
- 阐明ATP水解在由ACF调解的核细胞重塑过程中的不同作用.
主要方法:
- 单分子Förster共振能量转移 (smFRET) 用于实时监测ACF的单个核细胞重塑事件.
- 进行了动态分析,以确定在ACF介导核细胞体运动期间的中间状态和转位步骤.
主要成果:
- 沿着DNA进行ACF介导的核细胞转位以渐进的步骤发生,在大约7或3-4个基对运动后,具有明确的动态暂停的特征.
- ATP水解对于ACF结合,DNA转位和从动态暂停中释放至关重要,突出了三种不同的依赖ATP的功能.
- 在解离之前,ACF表现出高的过程性和双向性,能够反复地将核酶体前后转移.
结论:
- ACF作为一个过程性和双向的核酶转位酶,ATP水解驱动重塑周期的关键步骤.
- 这项研究揭示了ACF介导的核细胞重塑中的新型中间体和动态,进步了我们对染色质动态和基因沉默机制的理解.
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