染色质重塑蛋白复合物利用ATP水解能改变染色质结构调控基因的表达。作为细胞中基因表达的超级调控者，其亚基的突变与诸多疾病，包括癌症有着紧密的联系。在表观遗传学迅速发展的今天，还原生物分子相互作用的动态过程，探究基因表达调控的分子机制，进而揭示突变亚基致病机理是本领域研究的前沿课题之一。以前期工作为基础，本项目将利用高精度双光镊单分子技术研究染色质重塑蛋白RSC核心ATPase复合物的核小体驱除分子机制。拟以核小体DNA为模板，实时地追踪单个RSC复合物在核小体表面卷起DNA Loop及移位的动态过程。运用标记免疫标签、插入Anchor及酶切位点等方法，制备有三个核小体DNA特殊模板，巧妙地解析RSC复合物驱除核小体的分子机理。以此为切入点，深入地剖析染色质重塑蛋白复合物的重塑及组蛋白修饰调控机制，以及人类同源SWI/SNF中brg1、snf5等重要亚基的功能。

ATP-dependent chromatin remodelers modulate gene expression through dynamically altering nucleosome structures. As a super regulator for gene expression and regulation, the mutations in the subunits of remodelers are closely linked to many disease syndromes, including cancers. Revealing the real dynamics and therefore the molecular mechanisms of chromatin remodeling are the direct key for pathology of chromatin-related diseases. Based on my previous studies, I will employ the high-resolution optical tweezers to investigate the remodeling mechanism of ATPase core complex of RSC, with the emphasis on how the remodelers reject histones from nucleosomal DNA. A specially labeled reconstituted nucleosomal DNA which constituted of 3 individual nucleosomes will be utilized as the working templates for RSC core complexes in our single-molecule optical tweezers experiments. Combining with biochemical strategies, like inserting fusion anchors or restriction sites, single molecular experiments will allow us to dissect the rejection mechanisms of nucleosomes. Furthermore, we will explore the fundamental machinery for chromatin remodeling，regulation effects of Histone modification and the roles of the key subunits in SWI/SNF family, like brg1, snf5 etc.