STRUCTURAL MECHANISMS OF GTPASE AND PHOPHOINOSTIDE REGULATED TRAFFICKING

项目3的目的和目标 细胞表面受体、葡萄糖转运蛋白和其他血浆的内化和再循环 膜蛋白受磷酸肌醇代谢以及Rab和Arf的GTP酶调节 家庭这些调节机制的缺陷与多种疾病状态有关 包括癌症和II型糖尿病。项目3的长期目标是， 了解的机制，整合磷酸肌醇信号和Rab/Arf GT3激活与 介导/调节质膜和细胞内运输事件的动态分子组装体 内体系统为了达到这个目标，我们将联合收割机结合晶体学，生物化学， 生物物理学和突变的研究与互补的结构-功能分析， 与项目1、2、4和成像核心合作。根据前几次会议的意见， 融资期和广泛的新的初步数据，我们将：（目标1）研究结构性决定因素， Arf GTP酶Grp 1家族的自身调节和磷酸肌醇依赖性膜靶向 目的2.研究Rab的自身调节机制、膜靶向作用和Rab的表达。 通过Rabex-5/Rabaptin-5复合物和Rin 1激活;以及（目的3）探索 EHD的磷酸肌醇依赖性和非依赖性复合物对内吞再循环的调节 Rabenosyn-5、EHBP 1和FIP 2蛋白。 与公共卫生的相关性 II型糖尿病和癌症都涉及细胞表面受体的机制缺陷， 胰岛素和生长因子与控制细胞代谢的分子机制沟通， 增长通过在结构、分子和细胞水平上全面研究这些机制， 通过合作项目，联合收割机结合了结构、分子和细胞生物学家的专业知识，我们希望 以确定新的机制为基础的战略，可用于治疗干预。

Objective and Aims for Project 3 The internalization and recycling of cell surface receptors, glucose transporters, and other plasma membrane proteins is regulated by phosphoinositide metabolism as well as GTPases of the Rab and Arf families. Defects in these regulatory mechanisms have been implicated in a variety of disease states including cancer and type II diabetes. The long term objective of Project 3 is to characterize poorly understood mechanisms that integrate phosphoinositide signaling and Rab/Arf GTPase activation with the dynamic molecular assemblies that mediate/regulate trafficking events at the plasma membrane and within the endosomal system. To achieve this objective, we will combine crystallographic, biochemical, biophysical, and mutational studies on purified complexes with complementary structure-function analyses in collaboration with Projects 1, 2, 4, and the imaging core. Building on the observations of the previous funding period and extensive new preliminary data, we will: (Aim 1) examine the structural determinants of autoregulation and phosphoinositide dependent membrane targeting in the Grp1 family of Arf GTPase exchange factors; (Aim 2) investigate the mechanism of autoregulation, membrane targeting, and Rab activation by the Rabex-5/Rabaptin-5 complex and Rin1;and (Aim 3) explore the structural bases for regulation of endocytic recycling by phosphoinositide dependent and independent complexes of EHD proteins with Rabenosyn-5, EHBP1, and FIP2. Relevance to Public Health Both type II diabetes and cancer involve defects in the mechanisms by which cell surface receptors for insulin and growth factors communicate with the molecular machinery that controls cell metabolism and growth. By studying these mechanisms comprehensively at the structural, molecular, and cellular levels through collaborative projects the combine the expertise of structural, molecular, and cell biologists we hope to identify novel mechanism-based strategies that can be exploited for therapeutic intervention.