Contributions of protein aggregation to gene regulation and phenotypic diversity

描述（由申请人提供）：蛋白质的聚集与人类疾病密切相关，包括数十种家族性和年龄相关疾病，这些疾病共同构成了对我们老龄化人口的主要健康威胁。然而，最近的发现表明，蛋白质聚集也可以具有广泛的结构和调节功能。这种非病理性聚集的广度和普遍性在很大程度上尚未得到探索。在出芽酵母（Saccharomyces cerevisiae）中，多种内在无序蛋白（IDPs），包括转录因子、RNA结合蛋白和激酶，在生理条件下具有聚集的倾向。其中一种蛋白质，转录因子Mot3，是已知的少数几种能够形成自繁殖聚集体的蛋白质之一，这种聚集体作为遗传的蛋白质基础元件，或称朊病毒。通过从聚合状态切换到聚合状态，Mot3扩大了克隆酵母群体可获得的表型范围。这项工作的目标是：1)开发IDPs细胞内聚集的定量流式细胞仪报告，2)研究聚集对IDPs调节活性的影响，以及3)测试这些蛋白质，特别是Mot3的聚集是否是一种适应性生物学过程。这项工作将促进我们对非病理性蛋白质聚集的理解，同时为未来对活细胞中功能和疾病相关聚集的研究建立一个平台。

DESCRIPTION (provided by applicant): The aggregation of proteins is deeply associated with human diseases, including dozens of familial and age-associated disorders that together comprise a major emerging health threat to our aging populace. However, recent discoveries indicate that protein aggregation can also have a wide range of structural and regulatory functions. The breadth and pervasiveness of such non-pathological aggregation is largely unexplored. In the budding yeast, Saccharomyces cerevisiae, multiple intrinsically disordered proteins (IDPs), including transcription factors, RNA- binding proteins, and kinases, have a tendency to aggregate under physiological conditions. One such protein, the transcription factor Mot3, is one of only a handful of proteins known to form self-propagating aggregates that act as protein-based elements of inheritance, or prions. By switching to and from its aggregated state, Mot3 broadens the range of phenotypes accessible to clonal yeast populations. The goals of this work are to 1) develop a quantitative flow cytometric reporter for intracellular aggregation by IDPs, 2) investigate the consequences of aggregation on the regulatory activities of IDPs, and 3) test whether aggregation by these proteins, and by Mot3 in particular, is an adaptive biological process. This work will advance our understanding of non-pathological protein aggregation, while establishing a platform for future interrogations of both functional and disease-associated aggregation in living cells. PUBLIC HEALTH RELEVANCE: The aggregation of proteins is generally detrimental to their activities, and to human health. However, protein aggregates can also have important biological functions. This work will investigate the biological consequences of aggregation for a large class of previously identified aggregation-prone proteins in budding yeast. In the process, it will develop a powerful new approach for the interrogation of both functional and disease-associated protein aggregation in living cells.