Function and regulation of heterotrimeric G proteins in ciliogenesis and pathobiology of neurodevelopmental disorders

项目摘要 G蛋白偶联受体（GPCR）信号传导的许多组分，包括异源三聚体G（abg） 蛋白质定位于初级纤毛并调节它们的形态。虽然纤毛缺陷和G 蛋白质信号与神经发育障碍（NDD）有关，G 蛋白质调节纤毛形态发生或纤毛Ga信号传导的破坏有助于NDD的程度 仍然在很大程度上未知。该提案的总体目标是确定分子机制， RIC-8 -一种高度保守的GPCR非依赖性Ga蛋白激活剂-在感觉中塑造纤毛形态 神经元该应用的总体假设是RIC-8被动态地运输到感觉纤毛 并通过增强Ga信号传导来控制纤毛发生。这一假设将通过两个具体的 目标。在第一个目标下，体内蛋白质相互作用测定和基因组编辑方法将用于 机制上定义了RIC-8-Gai/o轴在控制纤毛形态发生中的功能作用。为 第二个目标，将建立一种由遗传、成像和体内蛋白质组学方法组成的协同方法， 应用于鉴定RIC-8纤毛运输和感觉神经元功能的分子调节剂。拟议 这项研究是创新的，因为它使用了一种全面的方法来定义RIC-8的一种新的细胞功能， 神经元发育中的Gai/o信号传导。这项研究意义重大，因为它有望建立 一个强有力的科学框架，用于研究睫状体RIC-8的分子组成和功能， C中的Gai/o信令网络。线虫和脊椎动物模型，并确定如何改变Ga蛋白信号 可能会导致神经发育障碍

PROJECT SUMMARY Many components of G-protein-coupled receptor (GPCR) signaling including heterotrimeric G (abg) proteins localize to primary cilia and modulate their morphology. Although cilia defects and dysregulated G protein signaling are associated with neurodevelopmental disorders (NDDs), the mechanisms by which G proteins regulate cilia morphogenesis or the extent to which disruption of ciliary Ga signaling contributes to NDDs remain largely unknown. The overall objective for this proposal is to define the molecular mechanisms by which RIC-8 – a highly conserved GPCR-independent activator of Ga proteins – shapes cilia morphology in sensory neurons. The overarching hypothesis for this application is that RIC-8 is dynamically trafficked to sensory cilia and controls ciliogenesis by potentiating Ga signaling. This hypothesis will be tested by pursuing two specific aims. Under the first aim, in vivo protein interaction assays and genome editing approaches will be used to mechanistically define the functional role of the RIC-8-Gai/o axis in controlling cilia morphogenesis. For the second aim, a synergistic approach comprised of genetic, imaging and in vivo proteomic approaches will be applied to identify molecular regulators of RIC-8 ciliary transport and function in sensory neurons. The proposed research is innovative because it uses a comprehensive approach to define a novel cellular function of RIC-8- Gai/o signaling in neuronal development. The proposed research is significant because it is expected to establish a strong scientific framework for investigations into the molecular composition and functions of the ciliary RIC-8- Gai/o signaling network(s) in C. elegans and vertebrate models and to determine how altered Ga-protein signaling may contribute to neurodevelopmental disorders.