Drs2p Function in Clathrin-coated Vesicle Budding

描述（申请人摘要）：真核细胞的一个显著特征， 从酵母菌到人类，是它们的隔室组织， 细胞器，每一个都有独特的组成和功能。的长期目标 这个研究项目是为了了解Goigi情结，一个 多室细胞器，在运输中发挥重要作用， 分泌途径中蛋白质的修饰和分选。为实现这一 目的：探讨ADP核糖基化因子（ARF）在囊泡介导的 从高尔基复合体的运输正在研究中。ARF似乎调节了 COPI和网格蛋白包被的囊泡从高尔基复合体中出芽。的 提出的研究源于最近的发现，涉及Drs2p的作用， 整合膜P型ATP酶和潜在脂质转位酶（或翻转酶）， 特别是在网格蛋白包被的囊泡的ARF依赖性出芽中。的 酵母酿酒酵母将用于这项工作，因为 所有真核细胞分泌途径的基本相似性 利用强大的基因和分子手段 使其成为理想的模型系统。本研究项目的具体目标是 以确定是否需要Drs2p将ARF和网格蛋白募集到高尔基体 因此，表明Drs2p在网格蛋白包被的囊泡中的直接作用 发芽将测试Drs2p的拟议脂质翻转酶活性，如将在下文中所述。 Drs2p和四种Drs2p相关蛋白之间潜在功能重叠 在酵母基因组中编码。这对人类有着深远的影响， 可以从这项研究中获得的健康。Drs2p和网格蛋白都是 在运输中高尔基复合体的正常功能所需的， 加工许多蛋白质。此外，与Drs2p相关的脂质翻转酶是 被认为限制磷脂酰丝氨酸（PS）的内部小叶的“血浆 膜的PS在血细胞中的这种不对称分布的丧失刺激了 凝块形成和凋亡细胞允许识别和吞噬 巨噬细胞

DESCRIPTION (APPLICANT'S ABSTRACT): A striking feature of eukaryotic cells, from yeast to human, is their compartmental organization into membrane-bound organelles, each with a unique composition and function. The long-term goal of this research project is to understand how the Goigi complex, a multi-compartment organelle, performs its essential role in the transport, modification and sorting of proteins in the secretory pathway. Towards this goal, the function of ADP-ribosylation factor (ARF) in vesicle-mediated transport from the Golgi complex is being examined. ARF appears to regulate the budding of both COPI- and clathrin-coated vesicles from the Golgi complex. The proposed studies stem from recent discoveries implicating a role for Drs2p, an integral membrane P-type ATPase and potential lipid translocase (or flippase), specifically in the ARF-dependent budding of clathrin coated vesicles. The yeast Saccharomyces cerevisiae will be used for this work because of the fundamental similarity of the secretory pathway in all eukaryotic cells coupled with the powerful genetic and molecular approaches available with this organism make it an ideal model system. The specific goals of this research project are to determine if Drs2p is required for recruiting ARF and clathrin to Golgi membranes, thus indicating a direct role for Drs2p in clathrin coated vesicle budding. The proposed lipid flippase activity of Drs2p will be tested as will the potential overlap in function between Drs2p and four Drs2p-related proteins encoded within the yeast genome. There are profound implications to human health that can be derived from this study. Both Drs2p and clathrin are required for the normal function of the Golgi complex in the transport and processing of many proteins. In addition, lipid flippases related to Drs2p are thought to restrict phosphatidylserine (PS) to the inner leaflet of 'the plasma membrane. Loss of this asymmetric distribution of PS in blood cells stimulates clot formation and in apoptotic cells allows for recognition and phagocytosis by macrophages.