MINORITY PREDOCTORAL FELLOWSHIP PROGRAM

描述(申请人提供)：蛋白质和细胞器的适当分布是真核细胞的基本特性。这种“极性”允许它们经历分裂、极化生长和分化等过程。建立极性的一种方法是引导细胞膜的运输。从酵母到哺乳动物，这种调节是一个保守的过程，所以这种调节如何发生的基本原理可以在酵母中发现，然后在动物模型中进行更详细的研究。我建议研究磷脂酰肌醇-4-磷酸(PI4P)在分泌中的作用，特别是评估它在Myo2p活动中的作用。Myo2p是一种马达蛋白，在细胞周期中负责几种细胞成分的运动和分离。它的货物之一是源自高尔基体的分泌囊泡。大量的证据表明，PI4P是高尔基体中主要的PI物种，此外，我们有初步的遗传学和影像数据表明，PI4P可能在依赖Myo2p的分泌囊泡运输中发挥作用。我计划通过各种遗传技术进一步研究这一点，即过表达抑制分析、突变体的产生和特征等。此外，我还将使用酵母双杂交的改良版本和传统的生化分析方法，试图鉴定难以捉摸的分泌囊泡Myo2受体。我的结果与实验室和其他地方的其他人一起，将有助于我们理解Myo2p是如何被调控的，这对细胞的生存至关重要。

DESCRIPTION (provided by applicant): Proper distribution of proteins and organelles is an essential property of eukaryotic cells. This "polarity" allows them to undergo processes like division, polarized growth, and differentiation. One way you can establish polarity is by directing membrane traffick. This regulation is a conserved process from yeast to mammals, so the basic principles of how that is occurring can be uncovered in yeast and then studied in more detail in animal models. I propose to study the role of phosphatidylinositol-4-phosphate (PI4P) in secretion, specifically, to evaluate its role in Myo2p activity. Myo2p is the motor protein responsible for the movement and segregation of several cellular components during the cell cycle. One of its cargoes is the secretory vesicles, that originate from the Golgi. Abundant evidence indicate that PI4P is the major PI species in the Golgi, plus we have preliminary genetic and imaging data suggesting that PI4P may play a role in Myo2p-dependent secretory vesicle transport. I plan to investigate this further by various genetic techniques, namely overexpression suppression analysis, generation and characterization of mutants, etc. Also, using modified versions of the yeast two-hybrid and conventional biochemical assays, I will try to identify the elusive secretory vesicle Myo2-receptor. My results, together with others in the lab and elsewhere, will help our understanding of how Myo2p is regulated, which is essential for the cell's survival.