EUKARYOTIC CHAPERONIN

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 分子伴侣是细胞折叠的关键介体。真核细胞伴侣蛋白trc/cct对于折叠一系列广泛的细胞蛋白是必不可少的。它的底物包括细胞分裂所必需的关键蛋白，如肌动蛋白、微管蛋白、细胞周期蛋白E和肿瘤抑制蛋白VHL。 TIC是一种1-丙二醛环状异寡聚复合体，它使用ATP结合和水解来驱动折叠周期。它由2个环组成，每个环含有8个不同但高度相似的亚基。人们对伴随着ATP结合和水解的构象变化知之甚少。我们最近进行了生化和生物物理研究，以表征其构象周期。低温电子显微镜的结构分析将为生化分析提供重要的补充。 这项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的蛋白质积累是许多疾病的分子基础，包括癌症、阿尔茨海默氏症和Prion疾病，强调了了解伴侣介导的折叠机制的重要性。因此，对伴侣如何在细胞中促进折叠的了解最终应该为在正常条件下以及在环境压力和疾病的异常情况下控制蛋白质功能提供基础。 TRIC是一种依赖于ATP的伴侣，有一个内置的盖子。我们使用生化方法和小角X射线散射的初步结果表明，在驱动盖子关闭和打开的水解循环期间，ATP发生了变化。与NCMI的合作将揭示TIC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。在另一组研究中，我们还将研究与电性结合的衬底的结构。这些研究将是我们机械、生化和生物物理研究的理想补充。

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.