Investigation of the yeast prion factor [PSI+]

酵母朊病毒因子的研究 [PSI ]

• 批准号: 8137097
• 负责人: SUSAN W LIEBMAN
• 金额: $ 42.43万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8137097
• 关键词: Address; Affect; Alzheimer' s Disease; Amino Acid Sequence; Amyloid; Appearance; Binding; Biochemical; Birth; Cattle; Cells; Chronic; Creutzfeldt-Jakob Syndrome; Deer; Disease; Drug Delivery Systems; Elements; Eukaryota; Fiber; Gene Expression Regulation; Genetic Models; Genetic Variation; Growth; Health; Homologous Gene; Human; Huntington Disease; Infection; Investigation; Light; Maintenance; Mammals; Mediating; Modeling; Molecular; Molecular Biology; Molecular Genetics; Nerve Degeneration; Neurodegenerative Disorders; Nucleic Acids; Orthologous Gene; Parkinson Disease; Pathology; Phenotype; Prion Diseases; Prions; Protein Binding; Protein Conformation; Protein S; Protein Structure Initiative; Proteins; Seeds; Stress; Structure; Testing; Titrations; Toxic effect; Variant; Yeast Model System; Yeasts; amyloid formation; conformer; epigenetic variation; fascinate; fungus; human Huntingtin protein; human disease; insight; novel; prion seeds; protein aggregate; protein misfolding; research study; solid state nuclear magnetic resonance; stress tolerance; sup35; wasting; yeast genetics; yeast prion

DESCRIPTION (provided by applicant): The misfolding of different cellular proteins into amyloid-like aggregates is associated with non- infectious neurodegenerative diseases including Alzheimer's, Huntington's and Parkinson's, as well as with the infectious prion diseases e.g. Mad Cow, Chronic Wasting in deer and Creutzfeldt-Jacob in humans. For each of these diseases, the associated protein aggregate ("seed') attracts its normal conformers to misfold and join the aggregate. Certain proteins in the simple eukaryote yeast, can likewise misfold into infectious amyloid aggregates, and these aggregates cause epigenetic variation. In this proposal, the power of yeast genetics and molecular biology is used to study how proteins misfold into amyloid-like aggregates and the consequences of this misfolding for the cell. The extensive similarity between yeast and human cells, which has enabled yeast models to make significant contributions in understanding human disease, implies that these studies will likely be relevant to misfolded aggregating proteins in humans. Since most human protein misfolding diseases occur without infection by any external seed, Aim I focuses on the molecular mechanisms surrounding spontaneous cellular amyloid formation. The questions addressed are: where do newly appearing prion aggregates first arise in cells, what other proteins are associated with them, and how do pre-existing prions enhance the de novo appearance of heterologous prions? Aim I also tests the hypothesis that Sla2, the yeast homolog of the mammalian huntingtin interacting protein, facilitates the ability of existing prions to cross-seed the de novo aggregation of heterologous prion proteins, by binding to both the seed and protein to be seeded, thereby placing them in close proximity. Interestingly, human and yeast prion proteins can each form multiple variants of amyloid aggregates that differ in structure and cause distinct phenotypes or disease pathologies, even though the amino acid sequences of the proteins are identical. Aim II identifies proteins bound to, and/or required for, the propagation of several prions and their variants. In addition, solid-state NMR structures of two variants of the same prion will be determined with the help of collaborators. By comparing heterologous prions, as well as different variants of the same prion, factors likely to be common to the maintenance and infectivity of all prions and that should therefore provide useful drug targets, will be identified. While amyloid formation is associated with disease, the actual cause of pathology is unclear. In Aim III, genetic and molecular studies of two prions that cause toxicity in yeast will help define the toxic species. Finally, yeast prions are important not only as a model for human disease, but also because they suggest an important new mechanism of genetic variation operating at the level of protein conformation rather than nucleic acids. In Aim IV the fascinating question of whether prions can sometimes provide the host cell with an advantage is explored, along with the possibility that such advantageous prions may also exist in mammals. PUBLIC HEALTH RELEVANCE: The power of yeast genetics and molecular biology will be used to study the misfolding of proteins into amyloid-like aggregates like those associated with several devastating neurodegenerative human diseases including Alzheimer's, Parkinson's, Huntington's and Creutzfeldt-Jacob's diseases. The extensive similarity between yeast and human cells, which has enabled yeast models to make significant contributions in understanding other human diseases, implies that the insights gained from these studies will be helpful when choosing drug-targets for the human diseases.

描述（由申请人提供）：不同细胞蛋白质错误折叠成淀粉样聚集体与非感染性神经变性疾病（包括阿尔茨海默氏病、亨廷顿病和帕金森氏病）以及感染性朊病毒疾病（例如疯牛病、鹿的慢性消瘦病和人类的克雅氏病）相关。对于这些疾病中的每一种，相关的蛋白质聚集体（“种子”）吸引其正常构象异构体错误折叠并加入聚集体。简单的真核生物酵母中的某些蛋白质同样可以错误折叠成感染性淀粉样蛋白聚集体，这些聚集体引起表观遗传变异。在这项提议中，酵母遗传学和分子生物学的力量被用来研究蛋白质如何错误折叠成淀粉样聚集体以及这种错误折叠对细胞的影响。酵母和人类细胞之间的广泛相似性使酵母模型能够在理解人类疾病方面做出重大贡献，这意味着这些研究可能与人类中错误折叠的聚集蛋白有关。由于大多数人类蛋白质错误折叠疾病的发生没有任何外部种子的感染，目的我专注于周围自发细胞淀粉样蛋白形成的分子机制。所涉及的问题是：新出现的朊病毒聚集体首先出现在细胞中的什么地方，与它们相关的其他蛋白质是什么，以及预先存在的朊病毒如何增强异源朊病毒的从头出现？目的我还测试的假设，即SLA 2，酵母同源物的哺乳动物亨廷顿蛋白相互作用蛋白，促进现有的朊病毒交叉播种的异源朊病毒蛋白的从头聚集的能力，通过结合到种子和蛋白质被播种，从而将它们放置在靠近。有趣的是，人类和酵母朊病毒蛋白可以各自形成淀粉样蛋白聚集体的多种变体，这些变体在结构上不同并导致不同的表型或疾病病理，即使蛋白质的氨基酸序列是相同的。目的II鉴定与几种朊病毒及其变体的繁殖结合和/或所需的蛋白质。此外，在合作者的帮助下，将确定同一朊病毒的两种变体的固态NMR结构。通过比较异源朊病毒以及相同朊病毒的不同变体，将鉴定可能对所有朊病毒的维持和感染性共同的因素，并且这些因素因此应该提供有用的药物靶点。虽然淀粉样蛋白的形成与疾病有关，但病理学的实际原因尚不清楚。在目标III中，对两种在酵母中引起毒性的朊病毒进行遗传和分子研究将有助于确定有毒物种。最后，酵母朊病毒的重要性不仅在于它是人类疾病的模型，而且还在于它提出了一种重要的新的遗传变异机制，这种遗传变异机制是在蛋白质构象而不是核酸水平上起作用的。在目标IV中，探索了朊病毒是否有时可以为宿主细胞提供优势的迷人问题，以及这种有利的朊病毒也可能存在于哺乳动物中的可能性，沿着。公共卫生关系：酵母遗传学和分子生物学的力量将用于研究蛋白质错误折叠成淀粉样聚集体，如与几种破坏性神经退行性人类疾病相关的聚集体，包括阿尔茨海默氏症，帕金森氏症，亨廷顿氏症和克罗伊茨费尔特-雅各布氏症。酵母和人类细胞之间的广泛相似性使酵母模型能够在理解其他人类疾病方面做出重大贡献，这意味着从这些研究中获得的见解将有助于为人类疾病选择药物靶点。