Spatial regulation of exocytosis

描述(申请人提供)：我的目标是了解Rho家族的小GTP酶是如何通过分泌囊泡对接复合体--胞囊来控制极化的胞吐作用的。胞吐作用的空间调控是许多生物过程的基础，如细胞生长、极性建立和细胞间通讯。这些基本过程的异常可能导致病理情况，如癌细胞转移、神经疾病和肾脏疾病。极化胞吐作用涉及分泌小泡与质膜特定区域的定向运输、对接和融合。“外囊”是一种进化上保守的多蛋白质复合体，专门定位于分泌活跃的部位，是质膜上基本的囊泡停靠机制。我们最近使用发芽酵母酿酒酵母的研究发现，Rho 1是Rho家族中的一个小GTP结合蛋白家族的成员，它与胞外相互作用，并在细胞周期的每个阶段调节胞外的定位。在这里，我们建议使用遗传学、细胞学和生物化学相结合的方法来鉴定和表征参与从Rho1到外囊的信号转导的蛋白质。此外，我们将检验我们的假设，即Rho 1与胞外成分相互作用，以促进它们在质膜上的极化组装。最后，我们将研究Rho 1如何协调胞吐作用与形态发生和极化细胞生长。这些研究对于我们理解控制真核细胞极化分泌的分子网络至关重要。

DESCRIPTION (provided by applicant): My goal is to understand how the Rho family of small GTPases control polarized exocytosis through the secretory vesicle docking complex, the exocyst. Spatial regulation of exocytosis is fundamental to many biological processes such as cell growth, polarity establishment, and cell-cell communication. Abnormalities in these fundamental processes may lead to pathological conditions such as cancer cell metastasis, neurological disorders, and kidney diseases. Polarized exocytosis involves directional transport, docking, and fusion of secretory vesicles with specific domains of the plasma membrane. An evolutionarily conserved multi-protein complex, the "exocyst" specifically localizes to sites of active secretion and serves as the basic vesicle docking machinery at the plasma membrane. Our recent studies using the budding yeast Saccharomyces cerevisiae revealed that Rho 1, a member of the Rho family of small GTP-binding proteins, interacts with the exocyst and regulate the localization of the exocyst during each stage of the cell cycle. Here we propose to identify and characterize the proteins involved in the signal transduction from Rho 1 to the exocyst using a combination of genetic, cytological, and biochemical approaches. Furthermore, we will test our hypothesis that Rho 1 interacts with the exocyst components to facilitate their polarized assembly at the plasma membrane. Finally, we will investigate how Rho 1 coordinates exocytosis with morphogenesis and polarized cell growth. These studies are crucial to our understanding of the molecular network controlling polarized secretion in eukaryotic cells.