STRUCTURE OF PROTEIN MODULES IN CHROMATIN REMODELING

染色质重塑中蛋白质模块的结构

• 批准号: 6769407
• 负责人: Ming-Ming Zhou
• 金额: $ 30.51万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2006-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6769407
• 关键词: acyltransferase; binding sites; chemical models; chromatin; computer simulation; gene induction /repression; genetic transcription; histones; nuclear magnetic resonance spectroscopy; protein binding; protein structure function; structural biology

DESCRIPTION: (Adapted from applicants abstract) Chromatin structural change plays a pivotal role in the regulation of gene transcription. Yet the molecular mechanisms of chromatin remodeling are not well understood. Eukaryotic DNA is packaged by wrapping around core histones to form nucleosomes and chromatin fiber. In order for the machinery of gene transcription to gain access to DNA, chromatin must undergo structural change, which is triggered by post-translational modifications on the histones. Recent yeast genetic and biochemical studies have led to the discovery of proteins and multi-protein complexes that act directly on chromatin to regulate transcription. Consonant with their essential roles in gene activation that controls numerous cellular processes, dysfunction of the chromatin-associated proteins has been implicated in various human diseases, particularly cancer. However, the specific function of many of these newly discovered proteins is poorly understood. The long term goal of this proposal is to develop an understanding of molecular mechanisms of chromatin remodeling and its role in gene activation. The approach is to focus on high-resolution structural and functional analysis of evolutionarily conserved protein modules found in chromatin-associated proteins. The recent structural and functional study by this laboratory of a histone-acetyltransferase (HAT) bromodomain showed that this highly conserved domain can specifically bind to acetyl-lysine on histones, providing the first evidence that bromodomains play a role in anchoring HATs and other co-activators onto active chromatin. Further investigations are proposed of ligand specificity of modules important for chromatin-mediated transcriptional activation, which include PHD finger (a zinc-binding protein) and SET domains. The specific aims are to determine three-dimensional structures using NMR, perform structure-based biochemical analysis to determine specificity of the modular domains, and develop high-affinity and selective peptide and non-peptide inhibitors of bromodomains, using a recently developed method for structure-based design of inhibitors by using NMR. It is expected that the results emerging from these studies will reveal new insights into the detailed molecular mechanisms used in chromatin remodeling and gene transcription, and could also lead to discovery of new drug targets for rational treatment of cancer.

描述：（改编自申请人摘要）染色质结构变化 在基因转录调控中发挥着关键作用。然而分子 染色质重塑的机制尚不清楚。真核生物的DNA是 通过包裹核心组蛋白来包装以形成核小体和染色质 纤维。为了让基因转录机制能够接触到 DNA， 染色质必须经历结构变化，这是由 组蛋白的翻译后修饰。最近的酵母遗传和 生化研究导致蛋白质和多种蛋白质的发现 直接作用于染色质以调节转录的复合物。辅音 其在控制众多细胞的基因激活中发挥重要作用 过程中，染色质相关蛋白的功能障碍与此有关 多种人类疾病，特别是癌症。不过具体功能 人们对许多新发现的蛋白质知之甚少。长期来看 该提案的目标是加深对分子机制的理解 染色质重塑及其在基因激活中的作用。方法就是集中注意力 进化的高分辨率结构和功能分析 在染色质相关蛋白中发现的保守蛋白模块。最近的 该实验室的结构和功能研究 组蛋白乙酰转移酶 (HAT) 溴结构域表明，这种高度保守的 结构域可以特异性结合组蛋白上的乙酰基赖氨酸，提供第一个 有证据表明溴结构域在锚定 HAT 和其他 共激活剂作用到活性染色质上。建议进一步调查 对染色质介导的转录很重要的模块的配体特异性 激活，其中包括 PHD Finger（一种锌结合蛋白）和 SET 结构域。 具体目标是使用 NMR 确定三维结构， 进行基于结构的生化分析以确定 模块化结构域，并开发高亲和力和选择性的肽和 溴结构域的非肽抑制剂，使用最近开发的方法 使用 NMR 进行基于结构的抑制剂设计。预计 这些研究的结果将揭示详细的新见解 用于染色质重塑和基因转录的分子机制，以及 还可能导致发现合理治疗的新药物靶点 癌症。