Mechanistic Analysis of Chromatin Remodeling

将DNA包装成染色质使其在很大程度上无法被 转录、复制、重组和修复。依赖于ATP的染色质重塑复合体发挥作用 使染色质具有动态化的关键作用。然而，这些络合物发挥作用的机制是 很大程度上是未知的。这项提案的总体目标是使用机械酶学的工具来 了解主要的依赖于ATP的染色质重塑复合体，人SWI/SNF是如何催化的 染色质中的DNA曝光。 SWI/SNF复合体在细胞内几个基因的转录调控中也起着关键作用。 基于周期的染色体结构调节。与这些角色一致的是，组件中的突变 其中，这些复合体与严重的发育缺陷和各种癌症有关。一个详细的 了解SWI/SNF机制将有助于深入了解其活动是如何受到监管的，以及如何 故障。这个项目的具体目标是： (1)确定导致DNA稳定暴露的染色质重塑的个别步骤 (2)确定SWI/SNF如何利用ATP结合和水解能重塑染色质 (3)剖析单个SWI/SNF亚基的机械性贡献

The packaging of DMAinto chromatin makes it largely inaccessible for the central nuclear processes of transcription, replication, recombination and repair. ATP-dependent chromatin remodeling complexes play a key role in making chromatin dynamic. However, the mechanisms by which these complexes function are largely unknown. The overall goal of this proposal is to use the tools of mechanistic enzymology to understand how a major ATP-dependent chromatin remodeling complex, human SWI/SNF, catalyzes exposure of DMAfrom chromatin. SWI/SNF complexes play crucial roles in the transcriptional regulation of several genes as well in the cell cycle based regulation of chromosome structure. Consistent with these roles, mutations in the components of these complexes are associated with severe developmental defects and a variety of cancers. A detailed understanding of SWI/SNF mechanism will provide insights into how its activity is regulated and how it malfunctions. The specific aims of this projectare: (1) To identify the individual steps in chromatin remodeling that lead to stable exposure of DNA (2) To determine how SWI/SNF uses the energy of ATP binding and hydrolysis for remodeling chromatin (3) To dissect the mechanistic contributions of individual SWI/SNF subunits