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：
8478955
负责人：
Linda Van Aelst
金额：
$ 48.18万
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 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8478955
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 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 hippocampal pyramidal neuron innovation insight nervous system disorder neuron development novel novel therapeutics prevent protein expression public health relevance 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分子机制，这些机制控制了独特类别的抑制性GABA能中间神经元的形态分化和功能成熟，称为枝形吊灯细胞（CHC）。这些细胞以其独特的轴突形态为特征并在保持适当的神经系统功能中发挥核心作用。值得注意的是，CHC形态和功能扰动在常见的脑疾病中，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在很大程度上未知。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RAC的Dock180家族成员Dock7/ZIR2（RAC的激活剂）在CHC的形态分化中的关键作用。通过实施一种创新方法，可以实现遗传标记和操纵单个CHC在开发小鼠胚胎中。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，迄今为止，尤其是唯一的其他蛋白质会影响CHC形态发生。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。该应用程序旨在进一步定义DOCK7在CHC中的作用，尤其是确定Dock7的分子途径是不可或缺的。针对这些目标，第一个目标将检验以下假设，即改变DOCK7的表达不仅会影响形态，而且会影响CHC的生理特性。具体而言，我们将通过GFP标记蛋白表达在转基因的小鼠系列中可视化的大量CHC中操纵DOCK7水平，这将允许对这些细胞进行电生理研究。 AIM 2专注于CHC中DOCK7的调节。我们猜想DOCK7充当ERBB4的下游效应子来控制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，并将进一步定义对这种相互作用和CHC中DOCK7功能重要的DOCK7调节元件。最后，AIM 3仔细检查了CHC中DOCK7下游的分子机制。我们的初步数据表明，与RAC依赖性和与RAC无关的途径都参与了CHC中Dock7的影响。因此，我们将努力表征RAC介导的信号通路，并确定使用创新的遗传和分子方法介导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，他们可以将新颖的光芒放在神经系统和精神障碍（例如癫痫和精神分裂症）基础的信号缺陷上。