Project 3: Structural basis of amyloid formation and chaperone-mediated turnover

项目摘要 目前还没有已知的治疗方法可以减缓或预防阿尔茨海默氏症和其他神经退行性疾病。 疾病，以及这些疾病进展的分子机制是很差的 明白我们的广泛目标是解决大分子结构测定中的关键问题， Aβ和tau朊病毒及相关蛋白调节复合物的疾病相关构象， 推进对朊病毒传播机制的理解并指导新的治疗方法。我们将 使用高分辨率冷冻电子显微镜（cryo-EM）方法实现这一目标，并：（1）开发亲和性 冷冻EM网格上的捕获方法，用于从组织中提取特定细丝以进行结构测定;（2） 确定来自体外组装和小鼠的Aβ和tau原纤维构象的冷冻-EM结构 模型，并与人体组织中确定的模型进行比较;（3）确定机制， Hsp 70分子伴侣机制调节朊病毒增殖、泛素化和 间隙有了这些目标，我们将确定淀粉样纤维的结构基础，在疾病的发展 并揭示关键的伴侣调节过程的质量控制和蛋白质的清除，形成 有毒的淀粉样蛋白

PROJECT SUMMARY Currently there are no known treatments that slow or prevent Alzheimer’s and other neurodegenerative diseases, and the molecular mechanisms that underlie the progression of these diseases are poorly understood. Our broad goal is to address critical problems in macromolecular structure determination of disease-relevant conformations of Aβ and tau prions and associated protein regulatory complexes in order to advance mechanistic understanding of prion propagation and guide novel therapeutic approaches. We will achieve this goal using high-resolution cryo-electron microscopy (cryo-EM) methods and: (1) Develop affinity capture methods on cryo-EM grids for extracting specific filaments from tissue for structure determination; (2) Determine cryo-EM structures of Aβ and tau fibril conformations derived from in vitro assembly and mouse models and compare with those determined from human tissue; and (3) Determine mechanisms and interactions by the Hsp70 molecular chaperone machinery that regulate prion propagation, ubiquitination, and clearance. With these goals we will identify the structural basis for amyloid fibrils that develop during disease and uncover key chaperone regulatory processes critical for quality control and clearance of proteins that form toxic amyloids.