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.

项目摘要/摘要 突触功能障碍是发展大量神经系统的主要贡献者 疾病。为了正确的形成，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充分理解。说唱鸟嘌呤交换因素或RAPGEF是 发挥作用的信号蛋白，可加速达到下游的GTPase激活速率 功能。 Rapgef亚家族成员与多种神经系统疾病有关，包括 精神分裂症。在鼠模型中，RAPGEF6功能的破坏导致焦虑降低 就像在精神分裂症患者中观察到的行为一样，并增加了长期增强。在 此外，他们发现总脑形态没有变化。尽管这些研究表明 RAPGEFS调节突触功能，确切的机制目前未知。解决 RAPGEF功能的丧失是否影响突触，PXF-1中的突变，秀丽隐杆线虫Rapgef 研究了直系同源物。当暴露于乙酰胆碱酯酶抑制剂Aldicarb时，PXF-1突变体 显示出降低的灵敏度，表明突触功能改变。此外，PXF-1和RAC-2 GTPase突变体在胆碱能突触中表现出降低的突触囊泡强度。基于 这些初步发现，中心假设是PXF-1改变了细胞骨架的重组 在神经元内影响突触形成并通过激活RAC来实现这一目标 GTPase信号传导。为了检验这一假设，本研究将使用秀丽隐杆线虫神经肌肉连接。 秀丽隐杆线虫是研究神经元功能的有利模型系统，因为它们的良好 定义的基因组，用于影像学技术的半透明体以及遗传操作的总体易用性。 该项目的目的是确定神经肌肉内PXF-1功能的机制 通过以下目标交界。目的1。确定pxf-1是的下游GTPase 在此途径中激活。目标2。研究是否抑制PXF-1中的间隙蛋白 途径可以恢复突触的发展和功能。总体而言，这项研究将提供有关 控制突触形成的分子机制以及它们的失调可能导致 疾病的发展。这项研究将支持开发未来治疗 突触病理学。