EUKARYOTIC CHAPERONIN

真核伴侣蛋白

• 批准号: 8361063
• 负责人: JUDITH FRYDMAN
• 金额: $ 6.13万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361063
• 关键词: ATP Hydrolysis; Actins; Adopted; Alzheimer' s Disease; Binding; Biochemical; Cell division; Cells; Collaborations; Complement; Complex; Cryoelectron Microscopy; Cyclin E; Disease; Electron Microscopy; Funding; Grant; Hydrolysis; Knowledge; Light; Malignant Neoplasms; Mediating; Mediator of activation protein; Methods; Molecular; Molecular Chaperones; Molecular Conformation; National Center for Research Resources; Principal Investigator; Prion Diseases; Proteins; Reaction; Research; Research Infrastructure; Resources; Roentgen Rays; Shapes; Source; Staging; Stress; Structure; Tubulin; United States National Institutes of Health; Von Hippel-Lindau Tumor Suppressor Protein; analog; base; chaperonin; cost; macromolecule; protein folding; protein function

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. 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.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 分子伴侣是细胞折叠的关键介质。真核生物伴侣蛋白 TRiC/CCT对于折叠多种细胞蛋白质是必不可少的。其基质包括关键的 细胞分裂所必需的蛋白质，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，其利用ATP结合， 水解以驱动折叠循环。它由2个环组成，包含8个不同的，但 每个环上都有高度相似的亚基对于这些蛋白质的构象变化， 伴随ATP结合和水解。 我们最近进行了生化和 生物物理研究，以表征其构象周期。结构分析， cryoEM将为生化分析提供重要补充。 研究的生物医学相关性：最近的发现表明，错误折叠和 错误折叠的蛋白质的积累是许多疾病的分子基础， 包括癌症，阿尔茨海默氏症和朊病毒疾病，强调了 了解分子伴侣介导的折叠机制。所以，知识是怎样的。 分子伴侣的功能是促进细胞内的折叠，这最终将为 在正常条件下控制蛋白质功能， 环境压力和疾病。 TRiC是具有内置盖的ATP依赖性伴侣蛋白。我们的初步结果使用 生物化学方法和小角X射线散射表明ATP的变化， 水解循环驱动盖子的关闭和打开。与NCMI的合作将 揭示了TRiC在ATP水解循环中所采用的构象。使用 模拟ATP水解反应的不同阶段的ATP类似物，我们将检测到 驱动伴侣蛋白介导的折叠的构象变化。在一个单独的套房里， 研究中，我们还将研究TRiC结合底物的结构。这些研究 将是对我们的机械生物化学和生物物理学研究的理想补充。