Rho regulator-mediated signaling in interneuron development

中间神经元发育中 Rho 调节器介导的信号传导

基本信息

批准号：
8829348
负责人：
Linda Van Aelst
金额：
$ 48.95万
依托单位：
COLD SPRING HARBOR LABORATORY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8829348
关键词：
Action Potentials Address Adolescent Adult Affect Awareness Axon Binding Biochemical Biochemical Genetics Brain Brain Diseases Brain Part Cells Cerebral cortex Complex DOCK1 protein Data Defect Development Diffuse Disease Electrophysiology (science)Elements Embryo Epilepsy Equilibrium ErbB4 gene Family member Gene Expression Genetic Glutamates Goals Guanosine Triphosphate Phosphohydrolases Health In Situ Interneurons Knowledge Label Laboratories Lead Light Link Mediating Mental disorders Methodology Methods Modeling Molecular Molecular Genetics Morphogenesis Morphology Motor Mus Nervous System Physiology Neurons Neurotransmitters Output Pathway interactions Physiological Physiology Play Population Presynaptic Terminals Property Proteins Receptor Protein-Tyrosine Kinases Regulation Regulatory Element Role Schizophrenia Sensory Process Signal Pathway Signal Transduction Structure Synapses Testing United States base excitatory neuron gamma-Aminobutyric Acid genetic approach hippocampal pyramidal neuron innovation insight nervous system disorder neuron development novel novel therapeutics prevent protein expression receptor rho rho GTP-Binding Proteins tool

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of this application is to define the molecular mechanisms that govern the morphological differentiation and functional maturation of a unique class of inhibitory GABAergic interneurons, called chandelier cells (ChCs). These cells are typified by their distinctive axonal morphology with arrays of boutons termed cartridges, and play a central role in maintaining proper nervous system function. Significantly, ChC morphological and functional perturbations are found in common brain disorders, including epilepsy and schizophrenia. Despite the importance of these cells, the molecular mechanisms that regulate ChC morphogenesis remain largely unknown. Our studies initiated to gain insight into the role of Rho regulators in GABAergic interneurons revealed a critical role for the DOCK180 family member DOCK7/Zir2, an activator of Rac, in the morphological differentiation of ChCs. This was made possible by implementing an innovative method that enables genetic labeling and manipulation of single ChCs in situ in developing mouse embryos. Furthermore, we recently found that DOCK7 forms a complex with the schizophrenia-linked ErbB4 tyrosine kinase receptor, which notably the only other protein is so far shown to affect ChC morphogenesis. These findings provide a unique entry point for studies of the molecular basis of ChC morphogenesis and function. This application aims to further define the role of DOCK7 in ChCs, and in particular to identify the molecular pathways DOCK7 is integral to. Towards these goals, the first aim will test the hypothesis that altered DOCK7 expression impacts not only the morphology but also the physiological properties of ChCs. Specifically, we will manipulate DOCK7 levels in a large population of ChCs visualized via GFP marker protein expression in a genetically modified mouse line, which will permit electrophysiology studies of these cells. Aim 2 focuses on the regulation of DOCK7 in ChCs. We conjecture that DOCK7 acts as downstream effectors of ErbB4 to control ChC morphogenesis and function. We will test this hypothesis using molecular, biochemical and genetic approaches and will further define DOCK7 regulatory elements important for this interaction and for DOCK7 function in ChCs. Finally, aim 3 scrutinizes molecular mechanisms downstream of DOCK7 in ChCs. Our preliminary data imply that both Rac-dependent and Rac-independent pathways are involved in mediating DOCK7's effects in ChCs. Hence, we will strive to characterize the Rac-mediated signaling pathways involved and identify novel molecular interactions that mediate DOCK7 function using innovative genetic and molecular approaches. The proposed studies will provide first/vital information on the molecular mechanisms governing ChC differentiation and function. As such, they could shed novel light onto the signaling defects that underlie neurological and mental disorders, such as epilepsy and schizophrenia.

描述（由申请人提供）：本申请的长期目标是定义控制一类独特的抑制性 GABA 能中间神经元（称为吊灯细胞（ChC））形态分化和功能成熟的分子机制。这些细胞的特点是其独特的轴突形态，具有称为盒的布顿阵列，并在维持正常的神经系统功能中发挥核心作用。值得注意的是，ChC 形态和功能扰动存在于常见的脑部疾病中，包括癫痫和精神分裂症。尽管这些细胞很重要，但调节 ChC 形态发生的分子机制仍然很大程度上未知。我们的研究旨在深入了解 Rho 调节剂在 GABA 能中间神经元中的作用，揭示了 DOCK180 家族成员 DOCK7/Zir2（Rac 的激活剂）在 ChC 形态分化中的关键作用。这是通过实施一种创新方法实现的，该方法能够在发育中的小鼠胚胎中对单个 ChC 进行原位基因标记和操作。此外，我们最近发现 DOCK7 与精神分裂症相关的 ErbB4 酪氨酸激酶受体形成复合物，这是迄今为止唯一被证明影响 ChC 形态发生的其他蛋白质。这些发现为研究 ChC 形态发生和功能的分子基础提供了独特的切入点。本申请旨在进一步明确 DOCK7 在 ChC 中的作用，特别是确定 DOCK7 所不可或缺的分子途径。为了实现这些目标，第一个目标将检验这样的假设：改变 DOCK7 表达不仅会影响 ChC 的形态，还会影响其生理特性。具体来说，我们将通过转基因小鼠系中的 GFP 标记蛋白表达来操纵大量 ChC 中的 DOCK7 水平，这将允许对这些细胞进行电生理学研究。目标 2 重点关注 ChC 中 DOCK7 的调节。我们推测 DOCK7 作为 ErbB4 的下游效应器来控制 ChC 形态发生和功能。我们将使用分子、生化和遗传方法检验这一假设，并将进一步定义对于这种相互作用和 ChC 中 DOCK7 功能重要的 DOCK7 调控元件。最后，目标 3 仔细研究 ChC 中 DOCK7 下游的分子机制。我们的初步数据表明 Rac 依赖性和 Rac 独立途径均参与介导 DOCK7 在 ChC 中的作用。因此，我们将努力表征所涉及的 Rac 介导的信号通路，并使用创新的遗传和分子方法鉴定介导 DOCK7 功能的新型分子相互作用。拟议的研究将提供有关控制 ChC 分化和功能的分子机制的第一/重要信息。因此，它们可以为神经系统和精神疾病（例如癫痫和精神分裂症）背后的信号缺陷提供新的线索。