Structure and assembly of the fungal prion HET-s

真菌朊病毒HET-s的结构和组装

• 批准号: 8201967
• 负责人: William N Wan
• 金额: $ 2.62万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2014-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8201967
• 关键词: Agreement; Alzheimer' s Disease; Amino Acid Sequence; Amyloid; Amyloid Fibrils; Asparagine; Behavior; Biological Models; Bovine Spongiform Encephalopathy; Brain; Cattle; Characteristics; Chronic Wasting Disease; Complex; Creutzfeldt-Jakob Syndrome; Crystallography; Data; Deer; Development; Disease; Electron Microscopy; Elements; Fiber; Fluorescence Spectroscopy; Genetic Polymorphism; Goals; Higher Order Chromatin Structure; Human; Hybrids; In Vitro; Indium; Infectious Agent; Joints; Link; Measures; Methodology; Methods; Modeling; Molecular; Molecular Structure; Nature; Neurodegenerative Disorders; Parkinson Disease; Pathology; Peptides; Phenotype; Podospora anserina; Prion Diseases; Prions; Process; Property; Proteins; Public Health; Publishing; Recording of previous events; Resolution; Roentgen Rays; Running; Scrapie; Sheep; Site-Directed Mutagenesis; Sodium Chloride; Structural Models; Structure; Symptoms; System; Techniques; Therapeutic; Variant; Work; X-Ray Crystallography; amyloid formation; amyloid structure; analog; base; fungus; human disease; in vivo; insight; meetings; prion-like; protein aggregate; protein folding; solid state nuclear magnetic resonance; therapy design; tool; yeast prion

DESCRIPTION (provided by applicant): Prions are aberrantly folded proteins implicated in the invariably fatal transmissible spongiform encephalopathies (TSEs). TSEs include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, chronic wasting disease (CWD) in deer and elk, and several forms of Creutzfeldt-Jakob disease (CJD) in humans. In addition to the TSEs, it has become apparent that other neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases, contain prion-like behavior in their pathologies. One common feature of these diseases is the aggregation of aberrantly folded proteins and peptides into amyloid fibrils. While the mechanism by which amyloid fibrils are involved in disease is unknown, differences in their molecular structures have been linked with differences in pathologies, a property called the strain phenomenon, which indicates that structure and pathology are interdependent. In order to understand the pathology of these diseases, it is imperative to determine the molecular structures of the implicated amyloids. However, this is a particularly difficult task owing to the heterogeneous and disordered nature of amyloid fibrils. In efforts to develop techniques, in addition to expanding our mechanistic understanding of amyloid formation, the proposed work aims to develop the prion forming domain of the functional fungal prion HET-s as a model system in studying the structure of pathological prions and prion-related amyloids. The HET-s prion forming domain, (218-289), is an ideal model system because infectious fibrils can be formed reproducibly and easily, but the domain still possesses a relatively complex fold comparable to those of pathologically relevant prions. The first aim will be to determine the structure of the infectious form of HET-s(218-289) using joint refinement methods between X-ray fiber diffraction and solid state NMR (ssNMR). The second aim will be to use site- directed mutagenesis to probe the necessity and redundancy of structural elements in correct folding of HET- s(218-289). The third aim will be to characterize infectious and several non-infectious species of HET-s(218- 289), which together can serve as an analog to the strain phenomenon. The methods of characterization will include X-ray fiber diffraction, fluorescence spectroscopy and electron microscopy. These aims will allow for a deeper understanding of the mechanism of prion folding as well as the critical elements necessary for correct folding. Characterization of HET-s(218-289) species, taken with the results of the first two aims, will provide insight into the interplay between environmental conditions and amino acid sequence that determine the final amyloid structure. While these studies cannot replace the need for studies of brain-derived prions, they provide a framework for understanding the mechanisms of prion folding and polymorphism. Preliminary results demonstrate the amenability of HET-s(218-289) to structure determination and biophysical characterization as well as its similarities to and subsequent extensibility in the study of pathological prions. PUBLIC HEALTH RELEVANCE: Prion diseases such as bovine spongiform encephalopathy (BSE) and Creutzfeldt-Jakob disease (CJD) as well as prion-related diseases such as Alzheimer's and Parkinson's diseases are a continually growing public health concern. The pathologies of these diseases are intricately associated with the molecular structures of aberrantly folded protein aggregates, termed amyloid, that are implicated in these diseases. The proposed studies aim to establish the fungal prion HET-s(218-289) as a model system in efforts to obtain useful structural and mechanistic information that will further advance efforts in the study of disease-associated amyloids.

描述（由申请人提供）：prions异常折叠的蛋白质涉及与致命的可传染性海绵状脑病（TSES）相关的蛋白质。 TSE包括绵羊中的草皮，牛的海绵状脑病（BSE），鹿和麋鹿中的慢性浪费疾病（CWD）以及人类中的几种形式的克鲁特兹菲尔德·贾科布病（CJD）。除TSE外，很明显，其他神经退行性疾病（例如阿尔茨海默氏病）和帕金森氏病在其病理学中含有类似prion的行为。这些疾病的一个共同特征是将异常折叠的蛋白质和肽聚集成淀粉样蛋白原纤维。虽然淀粉样蛋白原纤维参与疾病的机制尚不清楚，但其分子结构的差异与病理学的差异有关，这种特性称为菌株现象，这表明结构和病理相互依存。为了理解这些疾病的病理，必须确定所涉及的淀粉样蛋白的分子结构。但是，由于淀粉样蛋白纤维的异质性和无序性质，这是一项特别困难的任务。为了开发技术的努力，除了扩展我们对淀粉样蛋白形成的机械理解外，该提议的工作还旨在开发功能真菌prion het-S的prion型形成领域，作为研究病毒和prion相关淀粉样蛋白的结构的模型系统。 HET-S Prion形成域（218-289）是理想的模型系统，因为感染性原纤维可以重复地易于形成，但是该域仍然具有与病理相关的prions相当复杂的折叠。第一个目的是使用X射线纤维衍射和固态NMR（SSNMR）之间的联合改进方法来确定Het-S（218-289）传染性形式的结构。第二个目的是使用定向的诱变来探测结构元素在正确折叠中的必要性和冗余性（218-289）。第三个目的是表征感染性和几种非感染物种的Het-S（218-289），它们可以作为菌株现象的类似物。表征方法将包括X射线纤维衍射，荧光光谱和电子显微镜。这些目标将使人们更深入地了解prion折叠的机制以及正确折叠所需的关键要素。以前两个目标的结果进行的Het-S（218-289）物种的表征将洞悉确定最终淀粉样蛋白结构的环境条件和氨基酸序列之间的相互作用。尽管这些研究无法取代对脑衍生王室的研究的需求，但它们提供了一个理解prion折叠和多态性机制的框架。初步结果表明，HET-S（218-289）对结构确定和生物物理特征的结构及其与病理研究研究中的相似性以及随后的可扩展性相似。 公共卫生相关性：诸如牛海绵状脑病（BSE）和Creutzfeldt-Jakob疾病（CJD）以及与王室有关的疾病（例如阿尔茨海默氏症和帕金森氏病）等疾病的疾病持续越来越多。这些疾病的病理与异常折叠的蛋白质聚集体的分子结构相关，称为淀粉样蛋白，与这些疾病有关。拟议的研究旨在建立真菌prion het-s（218-289）作为模型系统，以获取有用的结构和机械信息，这些信息将进一步促进与疾病相关的淀粉样蛋白的研究。