EUKARYOTIC CHAPERONIN

真核伴侣蛋白

• 批准号: 8168533
• 负责人: JUDITH FRYDMAN
• 金额: $ 4.3万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-15 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8168533
• 关键词: ATP Hydrolysis; Actins; Adopted; Alzheimer' s Disease; Binding; Biochemical; Cell division; Cells; Collaborations; Complement; Complex; Computer Retrieval of Information on Scientific Projects Database; Cryoelectron Microscopy; Cyclin E; Disease; Funding; Grant; Hydrolysis; Institution; Knowledge; Light; Malignant Neoplasms; Mediating; Mediator of activation protein; Methods; Molecular; Molecular Chaperones; Molecular Conformation; Prion Diseases; Proteins; Reaction; Research; Research Personnel; Resources; Roentgen Rays; Shapes; Source; Staging; Stress; Structure; Tubulin; United States National Institutes of Health; Von Hippel-Lindau Tumor Suppressor Protein; analog; base; chaperonin; protein folding; protein function

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Molecular chaperones are key mediators of cellular folding. The eukaryotic chaperonin TRiC/CCT is essential to fold a wide array of cellular proteins. Its substrates include key proteins essential for cell division, such as actin, tubulin, cyclin E and the tumor suppressor protein VHL. TRiC is a 1 MDa ring-shaped hetero-oligomeric complex that uses ATP-binding and hydrolysis to drive the folding cycle. It is composed of 2 rings containing 8 different but highly similar subunits in each ring. Little is known about the conformational changes that accompany ATP-binding and hydrolysis. We have recently carried out biochemical and biophysical studies to characterize its conformational cycle. The structural analysis by cryoEM will provide a critical complement to the biochemical analysis. Biomedical relevance of the study: Recent findings indicating that misfolding and accumulation of incorrectly folded proteins is the molecular basis of many diseases, including cancer, Alzheimer's and Prion Diseases, underscore the importance of understanding the mechanisms of chaperone-mediated folding. Thus, knowledge of how chaperones function to promote folding in the cell should eventually provide the basis for controlling protein function under normal conditions, and during abnormal conditions of environmental stress and disease. TRiC is a ATP-dependent chaperonin with a built-in lid. Our preliminary results using biochemical methods and Small Angle X-ray Scattering indicate changes in ATP during the hydrolysis cycle drive the closing and opening of the lid. The collaboration with NCMI will shed light on the conformation adopted by TRiC during the ATP hydrolysis cycle. Using analogues of ATP that mimic distinct stages of the ATP hydrolysis reaction, we will detect the conformational changes that drive chaperonin-mediated folding. In a separate suite of studies, we will also investigate the structure of the TRiC-bound substrate. These studies will be an ideal complement to our mechanistic biochemical and biophysical studies.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 分子伴侣是细胞折叠的关键介质。真核伴侣蛋白 TRiC/CCT 对于折叠多种细胞蛋白至关重要。其底物包括细胞分裂所必需的关键蛋白质，例如肌动蛋白、微管蛋白、细胞周期蛋白 E 和肿瘤抑制蛋白 VHL。 TRiC 是一种 1 MDa 环状异源寡聚复合物，利用 ATP 结合和水解来驱动折叠循环。它由2个环组成，每个环中包含8个不同但高度相似的亚基。对于伴随 ATP 结合和水解的构象变化知之甚少。 我们最近进行了生物化学和生物物理研究来表征其构象循环。冷冻电镜的结构分析将为生化分析提供重要的补充。 该研究的生物医学相关性：最近的研究结果表明，错误折叠和错误折叠蛋白质的积累是许多疾病（包括癌症、阿尔茨海默病和朊病毒病）的分子基础，这强调了了解分子伴侣介导的折叠机制的重要性。因此，了解分子伴侣如何发挥作用以促进细胞折叠，最终将为在正常条件下以及环境应激和疾病的异常条件下控制蛋白质功能提供基础。 TRiC 是一种具有内置盖子的 ATP 依赖性伴侣蛋白。我们使用生化方法和小角 X 射线散射的初步结果表明，水解循环期间 ATP 的变化驱动了盖子的关闭和打开。与 NCMI 的合作将揭示 TRiC 在 ATP 水解循环中采用的构象。使用模拟 ATP 水解反应不同阶段的 ATP 类似物，我们将检测驱动伴侣蛋白介导的折叠的构象变化。在另一套研究中，我们还将研究 TRiC 结合底物的结构。这些研究将是对我们机械生化和生物物理研究的理想补充。