Role of C. elegans RAPGEF in Synapse Development at the Neuromuscular Junction

线虫 RAPGEF 在神经肌肉接头突触发育中的作用

• 批准号: 10676616
• 负责人: Reagan Elizabeth Mayfield Lamb
• 金额: $ 3.36万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10676616
• 关键词: Acceleration; Acetylcholinesterase Inhibitors; Actins; Address; Affect; Aldicarb; Animals; Appearance; Auxins; Behavior; Biological Assay; Biological Models; Biosensor; Caenorhabditis elegans; Calcium; Cholinergic Receptors; Complementary DNA; Copy Number Polymorphism; Cytoskeletal Modeling; Data; Defect; Development; Disease; Dissociation; Docking; Epilepsy; Exposure to; F-Actin; Fluorescence Microscopy; Functional disorder; Future; GTP Binding; GTPase-Activating Proteins; Genetic Diseases; Genetic Engineering; Genome; Goals; Guanine; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Heritability; Homologous Gene; Hydrolysis; Image; Imaging Techniques; Knowledge; Location; Long-Term Potentiation; Malignant Neoplasms; Mammals; Measures; Mediating; Mission; Molecular; Morphology; Mus; Mutation; Nature; Nervous System; Neuromuscular Junction; Neurons; Organism; Pathway interactions; Patients; Phenotype; Polymers; Population; Presynaptic Terminals; Proteins; Public Health; RAPGEF2 gene; Research; Role; Schizophrenia; Series; Signal Pathway; Signal Transduction; Signal Transduction Pathway; Signaling Protein; Stereotyping; Synapses; Synaptic Transmission; Synaptic Vesicles; System; Testing; Therapeutic; Tissues; Transmission Electron Microscopy; United States National Institutes of Health; Vesicle; Work; anxiety reduction; brain morphology; cholinergic synapse; connectome; density; disability; genetic manipulation; in vivo; insight; member; mouse model; mutant; nervous system disorder; neuronal circuitry; new therapeutic target; non-invasive imaging; polymerization; presynaptic; restoration; synaptic function; therapeutically effective

PROJECT SUMMARY/ABSTRACT Synaptic dysfunction is a major contributor towards the development of a large range of neurological disorders. For proper formation, synapses require a series of signaling pathways to guide them, but not all of those pathways are well understood. Rap Guanine Exchange Factors, or RapGEFs, are signaling proteins that act to accelerate the rate of activation of GTPases that achieve downstream functions. RAPGEF subfamily members are associated with multiple neurological disorders, including schizophrenia. In murine models, disruption of RAPGEF6 function results in reduced anxiety behaviors, like that observed in patients with schizophrenia, and increased long term potentiation. In addition, they found no changes in gross brain morphology. Although these studies suggest that RAPGEFs modulate synaptic function, the exact mechanism is currently unknown. To address whether loss of RapGEF function influences synapses, mutations within pxf-1, a C. elegans RapGEF orthologue were studied. When exposed to the acetylcholinesterase inhibitor, aldicarb, pxf-1 mutants displayed decreased sensitivity indicating altered synaptic function. Additionally, pxf-1 and rac-2 GTPase mutants display decreased synaptic vesicle intensity in cholinergic synapses. Based on these preliminary findings, the central hypothesis is that PXF-1 alters cytoskeletal reorganization within neurons to influence synaptic formation and accomplishes this through activation of Rac GTPase signaling. To test this hypothesis, this study will use the C. elegans neuromuscular junction. C. elegans are an advantageous model system for the study of neuronal function due to their well- defined genome, translucent body for imaging techniques, and overall ease of genetic manipulation. The goal of this project is to determine the mechanism of PXF-1 function within the neuromuscular junction through the following aims. Aim 1. To identify the downstream GTPase that PXF-1 is activating in this pathway. Aim 2. To investigate whether inhibiting a GAP protein in the PXF-1 pathway can restore synaptic development and function. Overall, this research will provide insight into the molecular mechanisms that govern synaptic formation and how their dysregulation may lead to development of disorders. This research will support the development of future treatments for synaptopathologies.

项目概要/摘要 突触功能障碍是一系列神经系统疾病发展的主要因素 失调。为了正确形成，突触需要一系列信号通路来引导它们，但是 并非所有这些途径都被充分理解。 Rap 鸟嘌呤交换因子 (RapGEF) 是 信号蛋白可加速 GTP 酶的激活速率，从而实现下游 功能。 RAPGEF 亚家族成员与多种神经系统疾病相关，包括 精神分裂症。在小鼠模型中，RAPGEF6 功能的破坏可减少焦虑 行为，就像在精神分裂症患者中观察到的那样，并增加了长时程增强。在 此外，他们发现大脑总体形态没有变化。尽管这些研究表明 RAPGEFs调节突触功能，具体机制目前未知。致地址 RapGEF 功能的丧失是否会影响突触、pxf-1（一种线虫 RapGEF）内的突变 研究了直系同源物。当暴露于乙酰胆碱酯酶抑制剂、涕灭威、pxf-1 突变体时 显示出敏感性降低，表明突触功能改变。此外，pxf-1 和 rac-2 GTPase 突变体表现出胆碱能突触中突触小泡强度降低。基于 这些初步发现的中心假设是 PXF-1 改变细胞骨架重组 神经元内影响突触形成并通过激活 Rac 来实现这一点 GTP 酶信号传导。为了检验这一假设，本研究将使用线虫神经肌肉接头。 秀丽隐杆线虫是研究神经元功能的有利模型系统，因为它们具有良好的 定义的基因组、用于成像技术的半透明体以及遗传操作的整体简易性。 该项目的目标是确定 PXF-1 在神经肌肉内的功能机制 结通过以下目标。目标 1. 鉴定 PXF-1 的下游 GTPase 激活该途径。目标 2. 研究是否抑制 PXF-1 中的 GAP 蛋白 途径可以恢复突触的发育和功能。总体而言，这项研究将深入了解 控制突触形成的分子机制以及它们的失调如何导致 疾病的发展。这项研究将支持未来治疗方法的开发 突触病理学。