Structure and Mechanism of a Prion-remodeling Factor

朊病毒重塑因子的结构和机制

• 批准号: 8670000
• 负责人: Francis T.F. Tsai
• 金额: $ 31.69万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8670000
• 关键词: Address; Adopted; Alzheimer' s Disease; Amyloid; Amyloidosis; Animal Model; Binding; Biochemical; Biological; Biology; Biotechnology; Bovine Spongiform Encephalopathy; Cells; Chemicals; Complex; Disease; Engineering; Family; Genetic; Grant; Health; Homeostasis; Homologous Gene; Human; Huntington Disease; Hybrids; In Vitro; Infection; Infectious Agent; Longevity; Maintenance; Mammals; Mediating; Membrane; Methods; Molecular; Molecular Chaperones; Molecular Conformation; Molecular Machines; Monitor; Mutagenesis; Neurodegenerative Disorders; Nonsense Codon; Pathology; Peptide Hydrolases; Peptides; Prion Diseases; Prions; Protein Family; Protein Structure Initiative; Proteins; Proteome; Proteomics; Reading; Recovery of Function; Research; Rewards; Risk; Role; Sorting - Cell Movement; Stress; Structure; Structure-Activity Relationship; Substrate Interaction; System; Tail; Techniques; Translations; Work; Yeasts; base; biological adaptation to stress; biophysical properties; conformer; in vivo; insight; nanomachine; nanomedicine; non-prion; novel; polypeptide; prevent; protein aggregate; protein aggregation; protein folding; protein misfolding; public health relevance; structural biology; termination factor; three dimensional structure; yeast genetics; yeast prion

DESCRIPTION (provided by applicant): Prions are unconventional, highly infectious agents, which are composed entirely of a protein that adopts an abnormal conformation. In mammals, prion-mediated infections are responsible for several devastating and invariably fatal neurodegenerative diseases, collectively known as transmissible spongiform encephalopathies. A hallmark of prion diseases is the presence of amyloids, which are also associated with the pathology of non-prion diseases, ranging from Alzheimer's and Huntington's disease to systemic amyloidosis. The broad and long-term research objective is to uncover the functional role of molecular chaperones in prion replication. Yeast provides an excellent paradigm to investigate the mechanism of prion replication. [PSI+] is a yeast prion that increases translational read-through of nonsense codons. Like mammalian prions, [PSI+] consist entirely of protein and is formed by self-replicating amyloid conformers of the evolutionary conserved translation termination factor Sup35p (eRF3). The inheritance and maintenance of [PSI+] are governed by Hsp104, a 600-kDa, ring-forming ATP-dependent, protein-remodeling machine, which cooperates with the Hsp70 chaperone system in prion replication and protein disaggregation. The objective of this research is to provide a detailed mechanistic understanding of the prion-remodeling and protein disaggregating activities of Hsp104 and its bacterial homolog ClpB. Three specific aims are proposed: 1) to determine the 3D structure of an Hsp104-substrate complex, 2) to investigate the synergistic interaction between Hsp104 and Hsp70/Hsp40, and 3) to elucidate the mechanism of protein disaggregation and prion replication by the Hsp104 bi-chaperone system. To address our research questions, we will use a multi-facet approach consisting of hybrid structural biology methods, proteomic and chemical biology techniques, and yeast genetics. The combination of these methods provides a powerful approach to yield new mechanistic insight into the structure-function relationship of this remarkable family of ATP-dependent molecular machines in order that this information might be exploited to engineer new nano-machines with novel biological activities with potential applications in biotechnology and nano-medicine.

描述（由申请人提供）：朊病毒是非常规的、高度传染性的病原体，其完全由采用异常构象的蛋白质组成。在哺乳动物中，朊病毒介导的感染导致几种毁灭性且致命的神经退行性疾病，统称为传染性海绵状脑病。朊病毒疾病的一个标志是淀粉样蛋白的存在，淀粉样蛋白也与非朊病毒疾病的病理学相关，从阿尔茨海默氏病、亨廷顿病到系统性淀粉样变性。广泛而长期的研究目标是揭示分子伴侣在朊病毒复制中的功能作用。酵母为研究朊病毒复制机制提供了一个极好的范例。 [PSI+] 是一种酵母朊病毒，可增加无义密码子的翻译通读。与哺乳动物朊病毒一样，[PSI+] 完全由蛋白质组成，由进化保守的翻译终止因子 Sup35p (eRF3) 的自我复制淀粉样蛋白构象异构体形成。 [PSI+] 的遗传和维持由 Hsp104 控制，Hsp104 是一种 600 kDa、成环 ATP 依赖性蛋白质重塑机器，它与 Hsp70 伴侣系统合作进行朊病毒复制和蛋白质解聚。本研究的目的是提供对 Hsp104 及其细菌同源物 ClpB 的朊病毒重塑和蛋白质解聚活性的详细机制了解。提出了三个具体目标：1) 确定 Hsp104-底物复合物的 3D 结构，2) 研究 Hsp104 和 Hsp70/Hsp40 之间的协同相互作用，3) 阐明 Hsp104 双伴侣系统蛋白质解聚和朊病毒复制的机制。为了解决我们的研究问题，我们将采用多方面的方法，包括混合结构生物学方法、蛋白质组学和化学生物学技术以及酵母遗传学。这些方法的结合提供了一种强大的方法，可以对这一非凡的 ATP 依赖性分子机器家族的结构-功能关系产生新的机制洞察，以便利用这些信息来设计具有新颖生物活性的新型纳米机器，并在生物技术和纳米医学方面具有潜在的应用。