Structural Biology of Sin3 Corepressor

描述(申请人提供)：真核基因表达的调控 在转录水平上依赖于多个 蛋白质因素。含多蛋白辅因子复合体的募集 序列特异性的染色质修饰和/或染色质重塑活性 DNA结合因子似乎是一种常见的、高度保守的机制 在许多启动子上调节基因转录。SIN3辅阻遏子复合体 是迄今为止在哺乳动物中发现的两种主要的抑制机制之一 细胞。这些对基因转录的负面影响 辅阻遏物复合体被认为部分依赖于组蛋白的作用。 脱乙酰酶(HDAC)，一组催化乙酰水解酶 来自乙酰化组蛋白底物的基团。SIN3辅阻遏子作为一种 一方面与HDAC1和HDAC2特异性结合的分子接头 以及一组令人惊讶的大而多样的转录因子 另一方面，在正常发展中发挥着至关重要的作用。这样做的结构基础 大分子缔合，这在严格的 对基因转录的调控，人们知之甚少。我们的研究将 解决基本问题，包括SIN3如何与其目标交互 原子水平，为什么它专门与这些目标相互作用，而不是与 其他，以及哪些残基对稳定性有重要贡献 这些大分子缔合。这些问题的答案在很大程度上取决于 关于详细的结构-功能分析。我们的主要工具是 研究将是高分辨率的液态核磁共振波谱，但我们 还将在必要时采用生化和其他生物物理方法。

DESCRIPTION (provided by applicant): Regulation of eukaryotic gene expression at the transcriptional level relies on the coordinated action of multiple protein factors. Recruitment of multi-protein cofactor complexes containing chromatin-modifying and/or chromatin-remodeling activities by sequence-specific DNA binding factors appears to be a common, highly conserved mechanism of regulating gene transcription at many promoters. The Sin3 corepressor complex is one of two major repression machineries identified thus far in mammalian cells. The negative influence on gene transcription exerted by these corepressor complexes is thought to rely in part on the action of histone deacetylases (HDACs), a group of enzymes that catalyze the hydrolysis of acetyl groups from acetylated histone substrates. The Sin3 corepressor functions as a molecular adapter specifically associating with HDAC1 and HDAC2 on the one hand and a surprisingly large and diverse group of transcription factors that play crucial roles in normal development on the other. The structural basis for such macromolecular associations, which has important implications in the strict regulation of gene transcription, is poorly understood. Our studies will address fundamental questions including, how Sin3 interacts with its targets at the atomic level, why it interacts specifically with these targets but not with others, and which residues make important contributions towards the stability of these macromolecular associations. Answers to these questions rely largely on detailed structure-function analyses. Our primary tool for these investigations will be high-resolution liquid-state NMR spectroscopy but we will also pursue biochemical and other biophysical approaches, as necessary.