Ribosome-Associated Regulation of Yeast Prion Formation

项目摘要/摘要 应激状态下淀粉样蛋白的形成是有益的，还是仅仅是一种病理现象 压力的结果是一个重要的开放问题。阐明细胞触发因素和生理机制 因此，淀粉样蛋白形成的后果是推进我们对 淀粉样蛋白生物学。申请者的长期目标是使用高度简便的酵母模型系统来理解 触发淀粉样蛋白形成的刺激，这种反应的潜在机制，以及它的生理 意义。这项提议的中心目标是破译核糖体相关的机制， 调节多种天然和人工酵母普里恩的形成及其对蛋白质形成的影响 基因表达和新陈代谢。中心假设是核糖体相关因子，如核糖体 核糖体相关复合体(RAC)和新生多肽相关复合体(NAC)起着核心作用 在对环境刺激的反应中调节普恩的形成，以及由此产生的普恩表型 重要的生理暗示。这一假设是基于申请者发表的作品和初步的 数据。这项拟议研究的基本原理是，阐明核糖体相关的贡献 蛋白形成过程是理解淀粉样蛋白的调节和生理影响的关键一步。 队形，以方便药理操作。使用自然产生的酵母蛋白[PSI+]，[URE3] 和[RNQ+]作为模型，以及人工构建的酵母蛋白，这一假说将通过追求来检验 两个相关但独立的特定目标：1)确定RAC和NAC在应激诱导蛋白中的作用 聚集和Pron的形成；以及2)确定Prion诱导对基因表达和 新陈代谢。拟议的工作具有创新性，因为它与现状有很大的不同 通过检查在Prion形成蛋白合成过程中Prion发生的最早时间点-- 并通过评估Pron转换的生理后果。此外，这些实验将是 申请者开发了一种创新的新Prion报告系统，使快速、 实时定量测量单个细胞中的Pron形成和Pron变异强度。这个 这项拟议研究的贡献有望在于阐明核糖体相关的机制。 调节淀粉样蛋白的形成及其对细胞生理的影响。这一贡献将是 意义重大，因为共翻译淀粉样蛋白的形成构成了最早的错误折叠事件， 药物干预可以是有针对性的；因此，了解潜在的触发因素和监管 共翻译淀粉样蛋白的发生机制是推动该领域发展的迫切需要，并可能提供一种 哺乳动物蛋白质错误折叠药理干预中靶向哺乳动物同系物的基础 精神错乱。

Project Summary/Abstract Whether amyloid formation in stress conditions serves any beneficial purpose or is instead simply a pathologic outcome of the stress is an important open question. Elucidating the cellular triggers and physiological consequences of amyloid formation therefore represents a critical barrier to advancing our understanding of amyloid biology. The applicant’s long-term goal is to use the highly facile yeast model system to understand the stimuli that trigger amyloid formation, the mechanisms underlying this response, and its physiological significance. The central objective of this proposal is to decipher the ribosome-associated mechanisms that regulate prion formation for a variety of natural and artificial yeast prions and the impact of prion formation on gene expression and metabolism. The central hypothesis is that ribosome-associated factors, such as the ribosome-associated complex (RAC) and the nascent polypeptide-associated complex (NAC), play a central role in regulating prion formation in response to environmental stimuli and that the resulting prion phenotypes have important physiological implications. The hypothesis is based on the applicant’s published work and preliminary data. The rationale for the proposed research is that elucidating the contributions of ribosome-associated processes in prion formation is a critical step in understanding the regulation and physiological impacts of amyloid formation to facilitate pharmacological manipulation. Using the naturally occurring yeast prions [PSI+], [URE3] and [RNQ+] as models, along with artificially constructed yeast prions, this hypothesis will be tested by pursuing two related but independent specific aims: 1) Identify the roles of RAC and NAC in stress-induced protein aggregation and prion formation; and 2) Determine the impact of prion induction on gene expression and metabolism. The proposed work is innovative because it represents a substantial departure from the status quo by examining the earliest possible time-point in prionogenesis – during synthesis of the prion-forming protein – and by assessing the physiological consequences of prion switching. Additionally, these experiments will be enriched by the applicant’s development of an innovative new prion reporter system that enables rapid, quantitative measurements of prion formation and prion variant strength in individual cells in real time. The contribution of the proposed research is expected to be the elucidation of ribosome-associated mechanisms regulating amyloid formation and the resulting consequences on cellular physiology. This contribution will be significant because co-translational amyloid formation constitutes the earliest misfolding event against which pharmacological intervention could be targeted; thus, an understanding of the underlying triggers and regulatory mechanisms of co-translational amyloidogenesis is urgently needed to advance the field and could provide a basis for targeting mammalian homologs in pharmacological interventions of mammalian protein misfolding disorders.