Structural basis of G protein mediated signaling

Rab GTP酶是多种细胞过程的重要调节因子，包括膜转运、细胞 生长、细胞器生物发生、膜重塑、信号转导和发育。拉布 GTP酶及其调节因子和效应器被认为与基因相关 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 GTP酶具有空间和时间重叠的分布 在由管状-囊泡细胞器组成的动态和高度互联的网络中 生物合成、内吞和循环利用系统。Rab GTP酶的功能进一步协调 通过具有两个或更多不同的Rab GTP酶结合结构域的多价蛋白质和复合体，每个 它对Rab GTP酶的亚群具有独特的特异性。 在人类基因组中编码了60种不同的蛋白质，Rab GTP酶代表了最大和最多的 RAS超家族的复杂分支。表征与结构不同的效应器的相互作用 调节因素，决定特异性，并破译识别的精细编码 决定因素是一个极其重要的挑战。在之前的资助期间，我们开发了， 优化并成功测试了一种多学科策略，用于在 Rab GTPase家族的成员。这项续期申请的长期目标是：i)概括这一点 尽可能多地研究效应器、调节因子和辅助蛋白；以及ii)扩展 确定候选Rab相互作用蛋白相互作用伙伴的方法。至 为了实现这些目标，我们将：(目标1)定量描述效应者和监管机构的特殊性 Rab GTPase家族的因子；(目标2)调查潜在的结构基础；(目标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分布的关键信息， 结构碱基和Rab GTP酶与效应子相互作用的序列决定因素， 调节因子和辅助蛋白。 与公共卫生的相关性 这些研究将揭示对细胞膜运输调控机制的新见解 生长和新陈代谢。所得到的信息可能被证明是有用的机构基础上的设计 治疗癌症和II型糖尿病的治疗学。

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.