Yeast as a gateway to conquering protein misfolding diseases.

受资助的父母补助金摘要。 某些蛋白质错误折叠，形成与疾病相关的自我播种的普恩样聚集体。我们只关注一件事 这样的蛋白质，TDP-43，因为它是与神经元聚集在一起的几种主要蛋白质 神经退行性疾病包括肌萎缩侧索硬化症(ALS)、额颞叶痴呆和晚期。 LATE是最近被描述的一种流行的TDP-43蛋白病，它会导致痴呆，经常被误诊 即阿尔茨海默病(AD)。此外，在与AD和帕金森氏症相关的聚集体中也发现了TDP-43。 由于TDP-43在酵母中形成聚集体并有毒(抑制生长)，因此是寻找治疗方法的有效途径 目标一直是识别修改TDP-43毒性的酵母基因。酵母菌模型与 人类疾病是显而易见的，因为几种酵母基因可以改变人类错误折叠疾病蛋白的毒性， 包括TDP-43在内，都是新的或已知的人类疾病风险因素的同源物。我们会继续研究 TDP-43聚集体在酵母中的发生和毒性基于我们对酵母自种蛋白的专门知识 蛋白质。我们希望了解TDP-43是如何对酵母造成毒性的，以及这与TDP-43有什么关系 对苍蝇、初级皮质神经元和小鼠的毒性。我们的目标之一是调查凝析油的范围， TDP-43形成的齐聚物和聚集体及其相关毒性。确定哪些物种 TDP-43的毒性最大，这是了解毒性机制的重要一步。它在很大程度上也是 有毒的TDP-43物种及其相关机制以什么细胞功能为靶标尚不清楚。我们会 识别和研究毒性的细胞靶点，重点是TDP-43功能毒性的获得。我们还将探索 通过研究TDP-43结合蛋白的过度表达是否可以 抑制TDP-43有毒物种的形成，如果TDP-43有毒物种滴定重要蛋白质 如果TDP-43的突变可以保护在同一细胞中表达的WT TDP-43不受 形成有毒的聚集体。我们寻求解决的另一个差距是为什么TDP-43与不同的 疾病。重要的是，正如我们所展示的酵母蛋白一样，TDP-43和其他疾病蛋白可以形成不同的 与突变无关的聚合体变异(菌株)，与不同的特征相关。因此， 不同的TDP-43变异体可以不同地影响神经元类型，例如引起ALS与迟发性。TDP-43变异体 建立在酵母中将是识别疾病特异性变异和促进发展的重要工具 不同的具体治疗方法。我们还将研究进入类液体颗粒是一种上游的观点 触发有毒物质的形成，以了解液体状颗粒是否为治疗靶点。我们将量化 普恩蛋白进入液体冷凝物与酵母中普恩随机形成的关系。 我们还将探索疾病相关代谢产物淀粉样聚集体的新领域，以及 假设它们核化类病毒/疾病蛋白错误折叠，就像我们所展示的交叉播种在 酵母蛋白。我们希望这项工作将为蛋白质错误折叠疾病带来新的治疗方法。

Abstract of the Funded Parent Grant. Certain proteins misfold to form self-seeding prion-like aggregates associated with disease. We focus on one such protein, TDP-43, because it is the major protein associated neuronal aggregates in several neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), frontotemporal dementia and LATE. LATE is a recently described prevalent TDP-43 proteinopathy that causes dementia that is often misdiagnosed as Alzheimer’s disease (AD). In addition, TDP-43 is found in aggregates associated with AD and Parkinson’s. Since TDP-43 forms aggregates and is toxic (inhibits growth) in yeast, a powerful approach to find therapeutic targets has been to identify yeast genes that modify TDP-43 toxicity. The relevance of the yeast model to human disease is clear because several yeast genes that modify toxicity of human misfolding disease proteins, including TDP-43, are homologs of new or known human disease risk factors. We will continue to study the genesis and toxicity of TDP-43 aggregates in yeast building on our expertise with yeast self-seeding prion proteins. We expect to learn how TDP-43 causes toxicity in yeast and in what ways this relates to TDP-43 toxicity in flies, primary cortical neurons and mice. One of our goals is to investigate the range of condensates, oligomers and aggregates formed by TDP-43 and their associated toxicities. Determining which species of TDP-43 is most toxic is an important step towards understanding of toxicity mechanisms. It is also largely unknown what cellular functions are targeted by toxic TDP-43 species and the affiliated mechanisms. We will identify and study cellular targets of toxicity focusing on TDP-43 gain of function toxicity. We will also explore new models of therapeutic approaches by investigating if overexpression of TDP-43 binding proteins can inhibit the formation of toxic TDP-43 species, if titration of important proteins by TDP-43 toxic species contributes to toxicity, and if mutations in TDP-43 can protect WT TDP-43 expressed in the same cell from forming toxic aggregates. Another gap we seek to address is why TDP-43 is associated with different diseases. Importantly, as we showed for yeast prions, TDP-43 and other disease proteins can form distinct aggregate variants (strains), unrelated to mutation, that are associated with distinct characteristics. Thus, different variants of TDP-43 could affect neuronal types differently causing e.g. ALS vs. LATE. TDP-43 variants established in yeast would be important tools to identify disease specific variants and facilitate development of variant specific treatments. We will also investigate the idea that entry into liquid-like granules is an upstream trigger for toxic species formation to learn if liquid-like granules are therapeutic targets. We will quantify the relationship between entry of prion proteins into liquid condensates and stochastic formation of prions in yeast. We will also explore the new area of disease associated metabolite amyloid-like aggregates and the hypothesis that they nucleate prion-like/disease protein misfolding much as we showed cross-seeding between yeast prions. We hope this work will lead to new treatment approaches for protein misfolding diseases.