Structural basis of G protein mediated signaling

Rab GTP酶是多种细胞过程的必需调节剂，包括膜运输、细胞增殖和细胞凋亡。 生长、细胞器生物发生、膜重塑、信号转导和发育。Rab GTP酶以及它们的调节因子和效应物已经牵涉到遗传相关的 疾病，复杂的疾病状态，如II型糖尿病和癌症，是毒力因子的目标 从病原体中分离出来许多Rab GTdR具有空间和时间重叠的分布 在动态和高度互连的网络的管状泡状细胞器，包括 生物合成、内吞和再循环系统。Rab GTP酶的功能进一步协调 通过具有两个或多个不同Rab GT3结合结构域的多价蛋白和复合物， 其对Rab GTP酶的亚类具有独特的特异性谱。 在人类基因组中编码有60种不同的蛋白质，Rab GTP酶代表了人类基因组中最大和最多的蛋白质。 Ras超家族的复杂分支。表征与结构多样的效应物的相互作用， 调节因素，确定特异性，破译识别的精细编码 决定因素是一个极其重要的挑战。在上一个融资期间，我们开发了， 优化，并成功地测试了一个多学科的战略，以解决识别问题的水平 拉伯·格特家族的成员本更新申请的长期目标是：i）推广这一点， 尽可能多的效应物，调节因子和辅助蛋白的方法;和ii）延长 结合候选Rab相互作用蛋白的相互作用配偶体的鉴定的方法。到 为了实现这些目标，我们将：（目标1）定量描述效应物和调节物的特异性， Rab GT家族的因素;（目的2）研究潜在的结构基础;（目的3）确定 观察到的特异性的主要决定因素。 这种实验策略的组合将提供关于特异性概况的关键信息， 结构碱基和Rab GTP酶与效应子相互作用的序列决定簇， 调节因子和辅助蛋白。 与公共卫生的相关性 这些研究将揭示新的见解调节膜运输的机制，细胞 生长和新陈代谢。由此产生的信息可能证明是有用的，在设计的机制， 用于治疗癌症和II型糖尿病的治疗剂。

Rab GTPases are essential regulators of diverse cellular processes including membrane trafficking, cell growth, organelle biogenesis, membrane remodeling, signaling transduction, and development. Rab GTPases as well as their regulatory factors and effectors have been implicated in genetically linked disorders, complex disease states such as type II diabetes and cancer, and are targets of virulence factors from pathogenic organisms. Many Rab GTPase have spatially and temporally overlapping distributions within the dynamic and highly interconnected network of tubular-vesicular organelles that comprise the biosynthetic, endocytic, and recycling systems. The functions of Rab GTPases are further coordinated through multivalent proteins and complexes with two or more distinct Rab GTPase binding domains, each of which has a unique specificity profile for subsets of Rab GTPases. With 60 distinct proteins encoded in the human genome, Rab GTPases represent the largest and most complex branch of the Ras superfamily. Characterizing interactions with structurally diverse effectors and regulatory factors, determining specificities, and deciphering the elaborate encoding of recognition determinants represents a critically important challenge. During the previous funding period, we developed, optimized, and successfully tested a multidisciplinary strategy for solving the recognition problem at the level of the Rab GTPase family. The long term objectives of this renewal application are to: i) generalize this approach to as many effectors, regulatory factors, and accessory proteins as possible; and ii) extend the methodology to incorporate identification of interaction partners for candidate Rab interacting proteins. To achieve these objectives, we will: (Aim 1) quantitatively profile the specificity of effectors and regulatory factors for the Rab GTPase family; (Aim 2) investigate the underlying structural bases; (Aim 3) identify the major determinants of the observed specificity. This combination of experimental strategies will provide critical information on the specificity profiles, structural bases, and sequence determinants underlying the interaction of Rab GTPases with effectors, regulatory factors, and accessory proteins. Relevance to Public Health These studies will reveal novel insights into the mechanisms for regulation of membrane trafficking, cell growth, and metabolism. The resulting information may prove useful in the design of mechanism based therapeutics for treatment of cancer and type II diabetes.