Structural Studies of Clp/Hsp 100 Molecular Chaperones

Clp/Hsp 100 分子伴侣的结构研究

• 批准号: 7002275
• 负责人: Francis T.F. Tsai
• 金额: $ 27.45万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7002275
• 关键词: X ray crystallography; adenosinetriphosphatase; bacterial proteins; caseins; conformation; cryoelectron microscopy; endopeptidases; enzyme activity; enzyme substrate; hydrolysis; molecular assembly /self assembly; molecular chaperones; protein structure function; stress proteins

DESCRIPTION (provided by applicant): Proteins must fold correctly in order to attain biological function. Concurrently, protein aggregation and misfolding are key contributors to many devastating human diseases such as Alzheimer's disease, prion-mediated infections, type II diabetes, and cystic fibrosis. While "conventional" molecular chaperones assist protein folding by promoting the "forward" folding or preventing protein aggregation, they are unable to promote the disaggregation of already aggregated proteins such as amyloids, which are associated with certain human diseases. Bacterial CIpB and its eukaryotic homolog Hsp104 are essential proteins of the heat-shock response, form large ring-like structures, and belong to the Hsp100 family of ATPases associated with diverse cellular activities (AAA+). Unlike any other chaperone, including other members of the Hsp100 family, CIpB/Hsp104 has the remarkable ability to promote the disaggregation of already aggregated, stress-damaged proteins. The underlying mechanism is currently unknown due to the lack of high-resolution structural information. The long-term objective is to understand the molecular mechanism by which members of the CIpB/Hsp104 family promote the disaggregation of stress-damaged proteins. The goals of this research will be pursued through the following specific aims: (1) to solve the high-resolution crystal structure of CIpB/Hsp104 using X-ray crystallography, (2) to elucidate the three-dimensional structure of the 0.6-MDa CIpB/Hsp104 assembly by cryo-electron microscopy, and (3) to determine the structural basis by which CIpB/Hsp104 recognizes and binds model substrates. These studies will be complemented by mutational and biochemical experiments to test the hypotheses inferred from these structures. The combination of these approaches will provide a detailed mechanistic understanding of the structure-function relationship of CIpB/Hsp104, and may inspire the design of novel technology that could lead to a potential cure for human prion and amyloid diseases.

描述（申请人提供）：蛋白质必须正确折叠才能获得生物学功能。同时，蛋白质的聚集和错误折叠是许多毁灭性人类疾病的关键因素，例如阿尔茨海默氏病，prion介导的感染，II型糖尿病和囊性纤维化。尽管“常规”分子伴侣通过促进“正向”折叠或预防蛋白质聚集来帮助蛋白质折叠，但它们无法促进与某些人类疾病有关的已经聚集的蛋白质（例如淀粉样蛋白）的分解。 细菌CIPB及其真核同源性HSP104是热震反应的必需蛋白质，形成大环状结构，属于与各种细胞活性相关的HSP100 ATPases家族（AAA+）。与任何其他伴侣（包括HSP100家族的其他成员）不同，CIPB/HSP104具有促进已经构成的，应损害的蛋白质分类的非凡能力。由于缺乏高分辨率结构信息，目前未知的基本机制。 长期目标是了解CIPB/HSP104家族成员促进应激损伤蛋白的分类的分子机制。这项研究的目标将通过以下特定目的来实现：（1）使用X射线晶体学求解CIPB/HSP104的高分辨率晶体结构，（2）以阐明0.6-MDA CIPB/HSP104的三维结构，以通过Cryo-Electron Microspopy和3）识别cip/3）来确定CIPSS的组装4基材。这些研究将通过突变和生化实验进行补充，以测试这些结构推断出的假设。这些方法的结合将提供对CIPB/HSP104结构功能关系的详细机械理解，并可能激发新技术的设计，这可能会导致对人类prion和淀粉样蛋白疾病的潜在治疗。