Ribosome-Associated Regulation of Yeast Prion Formation

项目总结/摘要 在应激条件下淀粉样蛋白的形成是否有任何有益的目的，或者仅仅是一种病理性的 压力的结果是一个重要的悬而未决的问题。阐明细胞触发和生理 因此，淀粉样蛋白形成的后果是推进我们对淀粉样蛋白的理解的关键障碍 淀粉样蛋白生物学申请人的长期目标是使用高度简易的酵母模型系统来理解酵母的功能。 触发淀粉样蛋白形成的刺激，这种反应的机制，及其生理 意义这项提议的中心目标是破译核糖体相关机制， 调节各种天然和人工酵母朊病毒的朊病毒形成，以及朊病毒形成对 基因表达和代谢。核心假设是核糖体相关因子，如 核糖体相关复合物（RAC）和新生多肽相关复合物（NAC）在细胞内起着重要作用 在调节朊病毒的形成，以响应环境刺激和由此产生的朊病毒表型， 重要的生理意义。该假设基于申请人已发表的工作和初步的 数据这项研究的基本原理是，阐明核糖体相关蛋白的贡献， 朊病毒形成过程是理解淀粉样蛋白调节和生理影响的关键步骤 形成以促进药理学操作。使用天然存在的酵母朊病毒[PSI +]，[URE3] 和[RNQ +]作为模型，沿着人工构建的酵母朊病毒，这一假设将通过以下方式进行检验： 两个相关但独立的具体目标：1）确定RAC和NAC在应激诱导蛋白中的作用， 聚集和朊病毒形成;和2）确定朊病毒诱导对基因表达的影响， 新陈代谢.拟议的工作是创新的，因为它代表着对现状的实质性偏离 通过检查朊病毒形成过程中最早可能的时间点-朊病毒形成蛋白的合成过程中- 以及评估朊病毒转换的生理后果。此外，这些实验将 通过申请人开发的一种创新的新朊病毒报告系统而丰富， 真实的实时定量测量单个细胞中朊病毒形成和朊病毒变体强度。的 这项研究的贡献预计将是阐明核糖体相关机制 调节淀粉样蛋白的形成和对细胞生理学的结果。这一贡献将是 这是重要的，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， 药物干预可能是有针对性的;因此，了解潜在的触发因素和调节因素， 迫切需要共同翻译淀粉样蛋白生成的机制来推动该领域的发展，并可以提供一个 在哺乳动物蛋白质错误折叠的药物干预中靶向哺乳动物同源物的基础 紊乱

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.