Signaling pathways that modulate neuronal activity

调节神经元活动的信号通路

基本信息

批准号：
9884109
负责人：
Michael Ailion
金额：
$ 37.47万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2023-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9884109
关键词：
Affect Animal Model Animals Behavior Binding Biochemical Caenorhabditis elegans Calcium Calcium Channel Cations Coupled Data Defect Development Disease Dopamine Dopamine Receptor Dyskinetic syndrome Electrophysiology (science)Extracellular Signal Regulated Kinases Functional disorder G alpha q Protein G protein coupled receptor kinase G-Protein Signaling Pathway G-Protein-Coupled Receptors GTP-Binding Protein alpha Subunits, Gs GTP-Binding Proteins Genetic Genetic Screening Goals Guanine Nucleotides Heterotrimeric GTP-Binding Proteins Human Intellectual functioning disability Interneurons Ion Channel Knock-out Lead Link Locomotion Medical Mitogen-Activated Protein Kinases Modeling Monomeric GTP-Binding Proteins Motor Neurons Muscle Contraction Muscle hypotonia Mutation Nematoda Neurons Output Pathway interactions Periodicity Phenotype Physiological Property Proteins Regulation Regulatory Pathway Role Scaffolding Protein Seizures Signal Pathway Signal Transduction Signal Transduction Pathway Site Sodium Channel Symptoms Work cellular imaging electrical property experimental study extracellular gene function innovation interdisciplinary approach interest member multidisciplinary mutant nervous system disorder neuronal circuitry neuronal excitability neuroregulation novel novel therapeutics receptor rho rho GTP-Binding Proteins synaptic function voltage

项目摘要

Project summary Neuronal activity can be modulated by transmitters that act through receptors coupled to heterotrimeric G proteins. Activation of these G protein signal transduction pathways may lead to the modulation of ion channels that alter neuronal excitability at the cellular level, ultimately causing changes in behavior at the organismal level. The long-term goal of our work is to identify and understand the mechanistic basis of neuromodulatory pathways. The goal of this proposal is to identify new regulatory pathways that lead to the modulation of a specific ion channel, the NALCN/NCA channel. The NALCN/NCA ion channel is a putative cation channel related to voltage-gated sodium and calcium channels, but whose precise cellular role and regulation are not well understood. However, mutations in NALCN or its associated subunits have been directly linked to human neurological diseases characterized by a range of symptoms, including abnormal movements and muscle contractions, intellectual disability, and seizures. Additionally, mutations in this channel in model organisms cause strong neuronal phenotypes including defects in rhythmic behaviors and neuronal excitability, demonstrating the physiological importance of this channel. Through a forward genetic screen in the nematode C. elegans, we found that the NCA ion channel is activated by a new signal transduction pathway acting downstream of the heterotrimeric G protein Gq. Activated Gq directly binds and stimulates the guanine nucleotide exchange activity of the Trio RhoGEF to activate the small G protein Rho, leading to the modulation of the NCA channel through unknown mechanisms. Here we will determine how Gq-Rho signaling modulates NCA activity by studying additional factors identified in our screen. In Aim 1, we will focus on the G protein- coupled receptor kinase GRK-2. Our genetic data support the hypothesis that GRK-2 modulates dopamine signaling that negatively regulates NCA activity through the Gq-Rho pathway. We will perform genetic, biochemical, cellular imaging, and electrophysiological experiments to determine how GRK-2 interacts with and affects the activity of dopamine receptors to eventually modulate the activity of the NCA channels. In Aim 2, we will focus on a mitogen-activated protein kinase (MAPK) pathway that modulates Gq-Rho activation of NCA. We will identify the members of this signaling pathway and determine how they modulate output of the Gq- Rho-NCA pathway. The proposed work is significant because it will identify the signaling pathways that modulate neuronal activity via a physiologically and medically important ion channel. The proposed work is innovative because it will close gaps in our understanding of how the NALCN/NCA ion channel is activated and identify new mechanisms of regulation of this channel.

项目概要神经元活动可以通过与异三聚体 G 偶联的受体发挥作用的递质来调节蛋白质。这些 G 蛋白信号转导途径的激活可能导致离子通道的调节改变细胞水平上的神经元兴奋性，最终导致有机体行为的变化等级。我们工作的长期目标是确定和理解神经调节的机制基础途径。该提案的目标是确定新的监管途径，从而调节特定离子通道，NALCN/NCA 通道。 NALCN/NCA 离子通道是假定的阳离子通道与电压门控钠通道和钙通道有关，但其精确的细胞作用和调节尚不清楚很好理解。然而，NALCN 或其相关亚基的突变已与人类直接相关。以一系列症状为特征的神经系统疾病，包括运动和肌肉异常宫缩、智力障碍和癫痫发作。此外，模式生物中该通道的突变引起强烈的神经元表型，包括节律行为和神经元兴奋性缺陷，证明了该通道的生理重要性。通过线虫的正向遗传筛选线虫中，我们发现 NCA 离子通道被一种新的信号转导途径激活异源三聚体 G 蛋白 Gq 的下游。活化的 Gq 直接结合并刺激鸟嘌呤 Trio RhoGEF 的核苷酸交换活性激活小 G 蛋白 Rho，从而导致调节通过未知机制控制 NCA 通道。在这里我们将确定 Gq-Rho 信号如何调节通过研究我们筛选中确定的其他因素来开展 NCA 活动。在目标 1 中，我们将重点关注 G 蛋白—— 偶联受体激酶GRK-2。我们的遗传数据支持 GRK-2 调节多巴胺的假设信号传导通过 Gq-Rho 途径负向调节 NCA 活性。我们将进行遗传、生化、细胞成像和电生理学实验，以确定 GRK-2 如何与影响多巴胺受体的活性，最终调节 NCA 通道的活性。在目标 2 中，我们将重点关注调节 NCA 的 Gq-Rho 激活的丝裂原激活蛋白激酶 (MAPK) 途径。我们将识别该信号通路的成员并确定它们如何调节 Gq-的输出 Rho-NCA 途径。拟议的工作意义重大，因为它将确定信号通路通过生理学和医学上重要的离子通道调节神经元活动。拟议的工作是创新，因为它将缩小我们对 NALCN/NCA 离子通道如何激活和理解的差距确定该渠道的新监管机制。