Role of beta-arrestins in G protein-coupled receptor sorting and signaling

项目说明 GPCR信号在多种生理过程中都是必不可少的。GPCR信令也可以发挥作用 在多种疾病的发病机制中发挥积极作用。GPCR通常受到严格监管，因此信号 适当的幅度和持续时间以及这些监管过程中的任何扰动 有害的。通常，G蛋白偶联受体激酶(GRKs)和G蛋白偶联受体激酶(GRKs)对GPCR信号进行严格调控。 --逮捕。阻滞素与质膜GRK磷酸化的GPCRs结合，通过以下途径终止信号 促进G蛋白解偶联和受体内吞作用。GRKs和β-的分子机制 阻滞剂对GPCR信号的调控仍然知之甚少。这项提议的目的是澄清 GRKs和阻滞素调控GPCR信号转导的分子机制。最近，我们描述了一种 阻滞素作为内小体分选分子的新功能，它们作用于内小体以 介导GPCRs从内体到溶酶体的分选，导致受体降解和长期 信号衰减。然而，对这一新功能缺乏机械性的洞察。？-arrestin-1介导 趋化因子受体CXCR4的内体分选，这也需要E3泛素连接酶的作用 AIP4和ESCRT(运输所需的内体分拣复合体)机械。如何-arrestin-1 与AIP4和ESCRT在功能上整合以介导CXCR4内体分选 下定决心。根据我们强大的初步数据，我们假设-arrestin-1调节ESCRT 控制CXCR4内体运输和信号传递的机制。我们提出以下两个具体目标： 目的1：确定α-arrestin-1与AIP4和ESCRTs结合的分子机制 控制CXCR4内体分选。目的2：确定ESCRT调控的分子机制 CXCR4信号和功能。我们将利用一系列最先进的生物化学， 分子和细胞生物学和成像方法，以实现这些目标。我们期待着新的 从这项提议中获得的知识将导致确定新的和创新的方法 操纵gpr信号来预防和治疗多种疾病。

Project Description GPCR signaling is essential for a wide variety of physiological processes. GPCR signaling can also play an active role in the pathogenesis of multiple diseases. GPCRs are normally tightly regulated so that signals are of the appropriate magnitude and duration and any perturbations in these regulatory processes can be deleterious. Typically, GPCR signaling is tightly regulated by G protein-coupled receptor kinases (GRKs) and ¿-arrestins. ¿-arrestins bind to GRK-phosphorylated GPCRs at the plasma membrane to terminate signaling by promoting G protein uncoupling and receptor endocytosis. The molecular mechanisms by which GRKs and ¿- arrestins regulate GPCR signaling remain poorly understood. The goal of this proposal is to elucidate the molecular mechanisms by which GRKs and ¿-arrestins govern GPCR signaling. Recently, we described a novel function for ¿-arrestins, as endosomal sorting molecules, whereby they function on endosomes to mediate sorting of GPCRs from endosomes to lysosomes, leading to receptor degradation and long-term attenuation of signaling. However, mechanistic insight into this new function is lacking. ¿-arrestin-1 mediates endosomal sorting of the chemokine receptor CXCR4, which also requires the action of the E3 ubiquitin ligase AIP4 and the ESCRT (endosomal sorting complex required for transport) machinery. How ¿-arrestin-1 functionally integrates with AIP4 and ESCRTs to mediate CXCR4 endosomal sorting remains to be determined. Based on our strong preliminary data we hypothesize that ¿-arrestin-1 regulates the ESCRT machinery to control CXCR4 endosomal trafficking and signaling. We propose the following two specific aims: Aim 1: To determine the molecular mechanisms by which ¿-arrestin-1 integrates with AIP4 and ESCRTs to control CXCR4 endosomal sorting. Aim 2: To determine the molecular mechanisms by which ESCRTs regulate CXCR4 signaling and function. We will utilize a comprehensive series of state-of-the-art biochemical, molecular and cellular biology and imaging approaches to complete these aims. We anticipate that new knowledge gained from this proposal will lead to the identification of new and innovative approaches to manipulate GPCR signaling to prevent and treat a variety of diseases.