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.

项目总结/摘要 突触功能障碍是导致大范围神经系统疾病发展的主要因素。 紊乱为了正确的形成，突触需要一系列的信号通路来引导它们， 并非所有这些途径都得到很好的理解。RAP鸟嘌呤交换因子，或RapGEF，是 信号蛋白，其作用是加速实现下游的GTP酶的活化速率， 功能协调发展的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，RAPGEF 6功能的破坏导致焦虑减少 行为，就像在精神分裂症患者中观察到的那样，并且增加了长时程增强。在 此外，他们没有发现大脑形态学的变化。尽管这些研究表明， RAPGEFs调节突触功能，确切的机制目前尚不清楚。解决 RapGEF功能的丧失是否影响突触、pxf-1内的突变、C.秀丽隐杆线虫RapGEF 直向同源物进行研究。当接触乙酰胆碱酯酶抑制剂涕灭威、pxf-1突变体时， 显示出灵敏度降低，表明突触功能改变。此外，pxf-1和rac-2 GT3突变体显示胆碱能突触中突触囊泡强度降低。基于 根据这些初步发现，中心假设是PXF-1改变细胞骨架重组 在神经元内影响突触形成，并通过激活Rac GT3信号。为了验证这一假设，本研究将使用C。神经肌肉接头 C.线虫是研究神经元功能的有利模型系统， 定义的基因组，成像技术的半透明体，以及遗传操作的整体简易性。 本项目的目标是确定PXF-1在神经肌肉中的作用机制， 通过以下目标的结合。目标1.为了鉴定PXF-1所处的下游GT酶， 在这条路上活跃。目标2.为了研究抑制PXF-1中的GAP蛋白是否 通路可以恢复突触发育和功能。总的来说，这项研究将提供深入了解 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的发展， 突触病理学