Chaperone Protein and Protein Conformational Switches

描述（由申请人提供）：在活细胞的高度拥挤的环境中，蛋白质难以折叠成其适当的结构，并且在面对其存在的正常磨损和撕裂时难以维持这些结构。错误折叠的蛋白质是导致人类一些最具破坏性的疾病的原因。但是折叠问题和生命本身一样古老。毫不奇怪，细胞用来科普它的机制（蛋白质伴侣，重塑因子，渗透调节剂和复杂的降解机制）是普遍使用和高度保守的。此外，现在看来，同样类型的错误折叠状态，在某些情况下可能是可怕的毒性，在其他情况下可能是有益的。这使我们能够使用易处理的模式生物来深入研究人类生物学和医学感兴趣的复杂蛋白质折叠问题。本申请的目的是利用酵母细胞和来自它们的蛋白质，研究一种特别重要的折叠类型，自模板淀粉样蛋白，以及蛋白质伴侣和重塑因子，这些因子控制它们的构象状态。我们将重点关注来自酵母酿酒酵母的两种此类蛋白质（Sup 35，Rnq 1）和来自加州海兔的一种蛋白质（CPEB）。在我们自己的实验室中使用一系列生物化学和遗传学方法，并与具有远远超过我们自己的生物物理专业知识的其他人合作，我们将a）确定由这三种蛋白质形成的淀粉样蛋白的基本结构框架，B）研究伴侣蛋白和合成化合物对体内和体外朊病毒成核和繁殖的影响，和c）研究为什么一些淀粉样蛋白生成构象异构体是有毒的而其他的不是。相关性：淀粉样蛋白是导致人类一些最具破坏性的疾病的原因，包括阿尔茨海默病，帕金森病和亨廷顿病。然而，我们仍然对有毒物种的性质知之甚少，更不用说治疗干预的明确途径了。酵母淀粉样蛋白经历非常相似的构象转换，更易于研究，这为淀粉样蛋白结构、构象变化和毒性状态的性质等非常困难的问题提供了更快进展的希望。

DESCRIPTION (provided by applicant): In the intensely crowded environment of living cells, proteins have difficulty folding into their proper structures and in maintaining these structures in face of the normal wear and tear of their existence. Misfolded proteins are responsible for some of the most devastating diseases of mankind. But the folding problem is as old as life itself. Not surprisingly, the mechanisms that cells use to cope with it (proteins chaperones, remodeling factors, osmolytes, and sophisticated degradation machineries) are universally employed and highly conserved. Moreover, it now appears that the same types of misfolded states that can be terribly toxic in some circumstances can be beneficial in others. This allows us to use tractable model organisms to study deeply complex protein folding problems that are of interest to human biology and medicine. This application aims to take advantage of yeast cells, and proteins derived from them, to investigate a particularly important type of fold, the self-templating amyloids, and the protein chaperones and remodeling factors that govern their conformational states. We will focus on two such proteins from the yeast Saccharomyces cerevisiae, Sup35, Rnq1, and one from Aplysia californica, CPEB. Using an array of biochemical and genetic methods in our own laboratory, and collaborating with others who have biophysical expertise far beyond our own, we will a) determine the basic structural framework of amyloids formed by the three proteins, b) investigate the effects of chaperones and synthetic compounds on prion nucleation and propagation in vivo and in vitro, and c) examine why some amyloidogenic conformers are toxic and others are not. Relevance: Amyloids are responsible for some of the most devastating diseases of mankind, including Alzheimers, Parkinsons, and Huntingtins Diseases. Yet we still have little understanding of the nature of the toxic species, much less a clear route to therapeutic intervention. Yeast amyloids undergo remarkably similar conformational conversions and are much more amenable to investigation, offering the hope of more rapid progress on the very difficult problems of amyloid structure, conformational change, and the nature of toxic states.