Molecular Regulation of Exocytosis

项目摘要 胞吐作用是由来自高尔基体的分泌囊泡的运输、对接和融合介导的 网络和内体的质膜。 由于胞吐作用集中参与， 控制，在从激素释放到胚胎发生的广泛生理过程中， 重要的是了解调节胞吐作用的分子机制。我们的研究重点是 胞吐途径中两个独立但相连的“模块”，Rab GTP酶和胞吐 复杂，这两个都是进化保守从酵母到人类。 在本提案中，我们将 首先研究控制Rabin 8激活的分子机制，Rabin 8是鸟嘌呤 Rab 8的核苷酸交换因子（GEF），Rab 8是哺乳动物细胞中胞吐作用的主要调节因子。我们 将研究磷脂酰肌醇和上游Rab蛋白Rab 11在激活中的作用， 拉宾8此外，我们还将通过以下方法研究Rabin 8 GEF活性的磷酸化和调节： 细胞外信号调节激酶1/2（ERK 1/2）对表皮生长因子（EGF）的应答 发信号。最后，我们将确定外囊在SNARE介导的膜融合中的作用。我们 采取多学科方法，结合生物化学，生物物理学，酵母遗传学和 显微成像来解决该领域的关键问题。 这些研究不仅能帮助我们 阐明在分子水平上的胞吐的调节机制，但也有助于我们 了解一些疾病，如糖尿病和多囊肾病（PKD）。

Project Summary Exocytosis is mediated by transport, docking and fusion of secretory vesicles from trans-Golgi network and endosomes to the plasma membrane. As exocytosis is centrally involved, and tightly controlled, in a wide range of physiological processes from hormone release to embryogenesis, it is important to understand the molecular mechanisms that regulate exocytosis. Our research focuses on two separate but connected "modules" in the exocytosis pathway, the Rab GTPases and the exocyst complex, both of which are evolutionarily conserved from yeast to humans. In this proposal, we will first investigate the molecular mechanisms that control the activation of Rabin8, which is the guanine nucleotide exchange factor (GEF) for Rab8, a major regulator of exocytosis in mammalian cells. We will examine the role of phosphatidylinositides and an upstream Rab protein, Rab11, in the activation of Rabin8. In addition, we will examine the phosphorylation and regulation of Rabin8 GEF activity by Extracellular signal-regulated kinases 1/2 (ERK1/2) in response epidermal growth factor (EGF) signaling. Finally, we will determine the role of the exocyst in SNARE-mediated membrane fusion. We take a multi-disciplinary approach combining biochemistry, biophysics, yeast genetics and microscopic imaging to address key questions in the field. These studies will not only help us elucidate the regulatory mechanisms of exocytosis at the molecular level, but also contribute to our understanding of a number of diseases such as diabetes and polycystic kidney diseases (PKD).