Non-canonical activation of heterotrimeric G protein signaling in vivo

异源三聚体 G 蛋白信号传导的体内非典型激活

基本信息

批准号：
10220082
负责人：
Mikel Garcia-Marcos
金额：
$ 43.13万
依托单位：
BOSTON UNIVERSITY MEDICAL CAMPUS
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-20 至 2023-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10220082
关键词：
Affect Animal Model Apical Binding Biochemical Biological Assay Biological Process Biosensor Brain Case Study Cell physiology Cells Congenital Abnormality Congenital Hydrocephalus Cues Cytoplasmic Protein Data Development Disease Edema Embryo Embryonic Development Encephalopathies Eukaryota Family Family member G-Protein-Coupled Receptors G-substrate GTP-Binding Proteins Genetic Goals Guanine Nucleotide Dissociation Inhibitors Guanine Nucleotide Exchange Factors Guanosine Triphosphate Health Heterotrimeric GTP-Binding Proteins Hormones Human Hydrocephalus Hypsarrhythmia In Vitro Intercellular Junctions Knowledge Measures Mediating Mediator of activation protein Molecular Mutate Neurodevelopmental Disorder Neurotransmitters Optic Atrophy Optics Pharmacology Physiological Processes Physiology Proteins Regulation Research Role Signal Transduction Signaling Protein Specificity Subgroup Syndrome System Visualization base cancer cell constriction drug market genetic regulatory protein human disease in vitro activity in vivo infancy innovation insight intercellular communication interest nervous system development neurodevelopment novel optogenetics protein activation prototype receptor recruit synthetic construct technological innovation tool

项目摘要

ABSTRACT SIGNIFICANCE: Heterotrimeric G proteins are quintessential mediators of intercellular communication. Defining the molecular mechanisms by which this widespread machinery is regulated is of paramount importance because it impacts a vast range of physiological processes and diseases. This is well exemplified by the ongoing research interest in G protein-coupled receptors (GPCRs), the canonical activators of heterotrimeric G proteins and the targets for >30% of marketed drugs. A much less studied aspect of heterotrimeric G protein regulation, but with far-reaching implications, is their “non-canonical” activation by proteins that are not GPCRs. Among these non-GPCR activators, proteins containing an evolutionarily conserved Gα-Binding-and- Activating (GBA) motif, namely “GBA proteins”, have emerged a key new players in the control of G protein signaling in health and disease. GIV and DAPLE are the prototype members of this family of G protein regulators and both of them are mutated in neurodevelopmental disorders in humans that result in brain birth defects. DAPLE is mutated in non-syndromic congenital hydrocephalus (NSCH) whereas GIV is mutated in Progressive Encephalopathy with edema, Hypsarrhythmia, and Optic atrophy (PEHO)-like syndrome. The cellular and molecular alterations that cause these diseases are poorly understood. BACKGROUND AND GOALS: One of our long-term goals to date has been to identify and characterize a family of cytoplasmic proteins with a GBA motif that activates G protein signaling. Like GPCRs, they have Guanine-nucleotide Exchange Factor (GEF) activity in vitro. Within this context, our goal here is to understand mechanistically how this in vitro GEF activity relates to activation of G proteins and G protein-dependent signaling in living cells, and to establish the importance of this mechanism in vivo. SYNOPSIS OF AIMS: We will (1) dissect how GIV and DAPLE, the two prototype GBAs, affect G protein signaling in cells by using novel chemogenetic platforms and G protein activity biosensors, (2) define how their function is regulated by extrinsic cues by using cell biological assays and novel optogenetic tools, and (3) characterize their impact on neurodevelopment by using animal models. INNOVATION AND IMPACT: Overall, we anticipate that this project will advance the field of heterotrimeric G protein signaling by providing detailed mechanistic insights into a poorly understood aspect of their regulation that impacts human health, and by generating a suite of chemogenetic, optogenetic and biosensor tools to directly manipulate and detect heterotrimeric G protein activity with unprecedented accuracy. The conceptual and technological innovations arising from the successful completion of this project would have a long lasting impact in the field of signal transduction.

抽象的意义：异三聚体 G 蛋白是细胞间通讯的典型介质。定义调节这种广泛存在的机制的分子机制至关重要重要性，因为它影响广泛的生理过程和疾病，这已经得到了很好的例证。通过对 G 蛋白偶联受体 (GPCR) 的持续研究兴趣，GPCR 是异三聚体 G 蛋白和超过 30% 的上市药物的靶标是一个研究较少的方面。异三聚体 G 蛋白的调节，但具有深远影响的是，它们的“非规范”激活是通过不是 GPCR 的蛋白质。在这些非 GPCR 激活剂中，含有进化保守的 Gα-Binding-and- 的蛋白质激活（GBA）基序，即“GBA蛋白”，已成为控制G蛋白的关键新参与者 GIV 和 DAPLE 是 G 蛋白家族的原型成员。调节因子，并且两者都会在人类神经发育障碍中发生突变，从而导致大脑诞生 DAPLE 在非综合征性先天性脑积水 (NSCH) 中发生突变，而 GIV 在非综合征性先天性脑积水中发生突变。进行性脑病伴有水肿、高度节律失常和视神经萎缩（PEHO）样综合征。人们对导致这些疾病的细胞和分子改变知之甚少。背景和目标：迄今为止，我们的长期目标之一是确定并描述一个具有激活 G 蛋白信号传导的 GBA 基序的细胞质蛋白家族，它们具有类似 GPCR 的功能。在此背景下，我们的目标是了解体外鸟嘌呤核苷酸交换因子 (GEF) 的活性。从机制上讲，这种体外 GEF 活性如何与 G 蛋白激活和 G 蛋白依赖性相关活细胞中的信号传导，并确定该机制在体内的重要性。目标概要：我们将 (1) 剖析 GIV 和 DAPLE 这两个原型 GBA 如何影响 G 蛋白通过使用新型化学遗传学平台和 G 蛋白活性生物传感器来研究细胞中的信号传导，(2) 定义它们如何通过使用细胞生物学和新型光遗传学工具、测定，通过外在信号调节功能和 (3) 通过使用动物模型来表征它们对神经发育的影响。创新和影响：总体而言，我们预计该项目将推动异三聚体 G 领域的发展通过对其调控的一个鲜为人知的方面提供详细的机制见解来研究蛋白质信号传导影响人类健康，并通过生成一套化学遗传学、光遗传学和生物传感器工具来以前所未有的准确性直接操纵和检测异源三聚体 G 蛋白活性。该项目的成功完成所产生的技术创新将具有持久的影响在信号转导领域的影响。