Structure/Mechanism of a Prion-remodeling Factor

朊病毒重塑因子的结构/机制

• 批准号: 7794934
• 负责人: Francis T.F. Tsai
• 金额: $ 30.39万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7794934
• 关键词: Address; Amyloid; Binding; Biochemical; Bovine Spongiform Encephalopathy; C-terminal; Cattle; Chronic Wasting Disease; Complex; Creutzfeldt-Jakob Syndrome; Deer; Disease; Family member; Goals; Human; In Vitro; Infection; Infectious Agent; Kuru; Molecular; Molecular Chaperones; Molecular Conformation; N-terminal; Neurodegenerative Disorders; Nonsense Codon; Prion Diseases; Prions; Protein Structure Initiative; Proteins; Proteomics; Reaction; Reading; Research; Resolution; Role; Stress; Structure; Techniques; Yeasts; amyloid fibril formation; base; biological adaptation to stress; conformer; design; in vivo; insight; prevent; prion hypothesis; prion-based; protein misfolding; release factor; research study; sup35; three dimensional structure; yeast prion

DESCRIPTION (provided by applicant): Prions are highly infectious proteinaceous agents responsible for several devastating and invariably fatal neurodegenerative diseases. Examples include Creutzfeldt-Jacob disease and kuru in humans, bovine spongiform encephalopathy in cattle, and chronic wasting diseases in elk and deer. The broad and long-term objective of our research is to further our molecular understanding of prions and prion diseases. [PSI+] is a yeast prion that increases translational read-through of nonsense codons. Like mammalian prions, yeast prions consist entirely of protein. [PSI+] is formed by self-replicating amyloid conformers of Sup35, which ultimately result in the formation of amyloid fibrils, a hallmark of prion diseases. Most interestingly, the inheritance, propagation, and elimination of [PSI+] are governed by the Hsp104 molecular chaperone. First discovered as an essential component in the yeast stress response, Hsp104 is an ATP-dependent protein- remodeling factor, which can rescue stress-damaged proteins from a previously aggregated state. While the ability to disaggregate proteins is shared with bacterial ClpB, ClpB neither promotes propagation nor facilitates elimination of [PSI+], suggesting that prion-remodeling and protein-disaggregating activities are mechanistically distinct. The goal of this proposal is to provide a detailed mechanistic understanding of the role of Hsp104 in prionogenesis. The following specific aims are proposed: (1) to determine the high-resolution crystal structure of Hsp104, (2) to dissect the biochemical mechanism of Hsp104 prion-remodeling activity, and (3) to determine the 3D structure of an Hsp104/Sup35 complex. To achieve our goals, we will combine three-dimensional structural studies with biochemical and high-throughput proteomic approaches. The combination of these techniques will provide substantial new insight into the mechanism of prion remodeling, an activity unique to Hsp104. Moreover, our proposed studies may also provide answers to why molecular chaperones cannot prevent prion infections, and may open new avenues in the search for a potential treatment of prion infections and other protein misfolding diseases. Prions are unconventional, highly infectious agents, responsible for several devastating and invariably fatal neurodegenerative diseases collectively known as transmissible spongiform encephalopathies. Molecular chaperones provide the first line of defense against prion infections and other protein misfolding diseases. Here we will investigate the structure and mechanism of Hsp104, a prion-remodeling factor and essential molecular chaperone of the stress response.

描述（由申请人提供）：prions是高度感染性的蛋白质剂，导致几种毁灭性和不变致命的神经退行性疾病。例子包括人类的creutzfeldt-jacob病和库鲁，牛的牛海绵状脑病以及麋鹿和鹿的慢性浪费疾病。我们研究的广泛和长期目标是进一步分子对王室和王室疾病的理解。 [PSI+]是一种酵母菌prion，可以增加无意码密码子的翻译通读。像哺乳动物的王室一样，酵母菌完全由蛋白质组成。 [PSI+]是由Sup35的自我复制淀粉样蛋白构象形成的，最终导致形成淀粉样蛋白原纤维，淀粉样蛋白纤维是Prion疾病的标志。最有趣的是，[PSI+]的遗传，传播和消除受HSP104分子伴侣的控制。 HSP104最初是作为酵母应力反应中的必不可少的组成部分发现的，它是ATP依赖性蛋白质重塑因子，可以从先前聚集的状态中挽救应激损害的蛋白质。虽然与细菌CLPB共享分解蛋白质的能力，但CLPB既不促进传播，也不促进消除[PSI+]，这表明prion型复制和蛋白质 - 污染活性在机械上是不同的。 该提案的目的是对HSP104在Prionogenesewosen中的作用提供详细的机械理解。提出了以下特定目的：（1）确定Hsp104，（2）的高分辨率晶体结构，以剖定HSP104 Prion-RemodeLewist活性的生化机理，以及（3）以确定HSP104/SUP35复合物的HSP104/SUP35复合物的3D结构。为了实现我们的目标，我们将将三维结构研究与生化和高通量蛋白质组学方法相结合。这些技术的结合将为prion重塑的机理提供大量新的见解，这是HSP104独有的活动。此外，我们提出的研究还可以提供答案，说明为什么分子伴侣无法预防毒品感染，并可能在寻找对prion感染和其他蛋白质错误折叠疾病的潜在治疗方面打开新的途径。 王室是非常规的，高度传染性的药物，导致了几种毁灭性和致命的神经退行性疾病，统称为可传染性海绵状脑病。分子伴侣提供了针对病毒感染和其他蛋白质错误折叠疾病的第一道防线。在这里，我们将研究HSP104的结构和机制，HSP104是应力反应的prion型复制因子和必需的分子伴侣。