Adhesion-dependent inhibition of RhoA through Arg tyrosine kinase and p190RhoGAP

通过 Arg 酪氨酸激酶和 p190RhoGAP 对 RhoA 进行粘附依赖性抑制

• 批准号: 7564757
• 负责人: William Daniel Bradley
• 金额: $ 2.55万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7564757
• 关键词: Actomyosin; Adhesions; Affect; Autistic Disorder; Axon; Biosensor; Brain; Cell membrane; Cells; Cellular Morphology; Cues; Cytoskeleton; Dendrites; Development; Disease; Event; Exhibits; Extracellular Matrix; Fibroblasts; GTPase-Activating Proteins; Gene Activation; Genes; Goals; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate; Human; Hydrolysis; Integrins; Knowledge; Laboratories; Lead; Life; Ligands; Light; Link; Maintenance; Mediating; Mental disorders; Monitor; Mood Disorders; Morphogenesis; Morphology; Neurites; Neurons; Pathway interactions; Phosphorylation; Phosphotransferases; Play; Process; Protein Tyrosine Kinase; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Reporter; Research; Role; Schizophrenia; Signal Transduction; Structure; Synapses; Time; base; extracellular; in vivo; inhibitor/antagonist; nervous system development; neural circuit; novel strategies; prevent; receptor; repaired; research study; response; rho; rho GTP-Binding Proteins; tool

DESCRIPTION (provided by applicant): Proper function of the human brain requires precise regulation during development and maintenance throughout adulthood. For neurons to function and signal properly, synaptic contacts between them are made using axons and dendrites that grow and branch in response to environmental cues. Numerous psychiatric disorders, such as schizophrenia, autism, and mood disorders exhibit reduced and aberrant connections between neurons. The RhoA GTPase (Rho) is an essential regulator of the cytoskeleton, and changes in its activity lead to alterations in the connections extension and retractions of axons and dendrites. Rho activity is controlled by activating guanine nucleotide exchange factors (GEFs) and inhibitory GTPase activating proteins (GAPs). One such regulator, p190RhoGAP (p190), plays a key role in inhibiting Rho and preventing the retraction of neurites and likely maintaining synaptic integrity. p190 is phosphorylated and activated by the non-receptor tyrosine kinase Arg (Abl-related gene) in response to integrin-mediated adhesion. Arg also plays a crucial role in neuronal maintenance, as neurons lacking Arg display reduced a drastic reduction in dendrite number and branching. Despite the correlative evidence linking Arg, p190, and Rho to neuronal structure and function, there is little mechanistic detail directly relating the proteins. The experiments I propose here will shed light on the pathway linking Arg-mediated p190 inhibition of Rho to changes in the cytoskeleton and morphology of fibroblasts and neurons. In the first aim I will define the mechanism of Arg activation in response to integrin-mediated adhesion. In the second aim I will develop probes necessary for observing real time changes in p190 activation and localization, Rho activity, and cytoskeletal and cell morphological changes necessary to directly link these events in this pathway. In the third aim, using the probes developed in aim 2, I will simultaneously monitor how the localized activity of p190 and its inhibition of Rho affect cytoskeletal and morphological dynamics in fibroblasts and neurons. Together these studies will provide much needed mechanistic detail relating Arg- mediated p190 inhibition of Rho with changes in the cytoskeleton and cell morphology. This will provide evidence highlighting the roles Arg, p190, and Rho play in maintenance and disruption of neuronal morphology. The long term goal is to reveal novel strategies for manipulating Rho activity to prevent the deleterious effects its dysregulation has on dendritic structure in hopes of preventing or treating psychiatric disorders, such as schizophrenia, autism, and mood disorders.

描述（由申请人提供）：人脑的适当功能需要在整个成年期间开发和维护过程中进行精确的调节。为了使神经元正常运行和信号，它们之间的突触接触是使用轴突和树突对环境提示进行生长和分支的树突进行的。精神分裂症，自闭症和情绪障碍等许多精神疾病在神经元之间表现出降低和异常的联系。 RhoA GTPase（Rho）是细胞骨架的必要调节剂，其活性的变化导致连接延伸和轴突和树突的缩回的改变。 RHO活性通过激活鸟嘌呤核苷酸交换因子（GEF）和抑制性GTPase激活蛋白（GAPS）来控制。一个这样的调节剂P190RHOGAP（P190）在抑制RHO和防止神经突的缩回并可能维持突触完整性方面起着关键作用。 P190被非受体酪氨酸激酶ARG（ABL相关基因）磷酸化并激活，以响应整联蛋白介导的粘附。 ARG在神经元维持中也起着至关重要的作用，因为缺乏ARG的神经元显示了树突数量和分支的急剧减少。尽管与ARG，P190和RHO与神经元结构和功能联系起来的相关证据，但几乎没有机械细节直接将蛋白质与蛋白质有关。我在这里提出的实验将阐明将RHO抑制与成纤维细胞和神经元的细胞骨架和形态的变化联系起来的途径。在第一个目的中，我将定义响应整联蛋白介导的粘附的ARG激活的机理。在第二个目标中，我将开发出观察到P190激活和定位，RHO活性以及细胞骨架和细胞形态变化的实时变化所必需的探针，以直接将这些事件直接连接到该途径中。在第三个目标中，使用AIM 2中开发的探针，我将同时监测P190的局部活性及其对RHO的抑制作用如何影响成纤维细胞和神经元中的细胞骨架和形态动力学。这些研究将共同​​提供急需的机械细节，将RHO抑制与细胞骨架和细胞形态变化有关。这将提供证据，强调ARG，P190和RHO在维持和破坏神经元形态中的作用。长期的目标是揭示操纵Rho活动的新策略，以防止其失调对树突结构的有害影响，以期预防或治疗精神疾病，例如精神分裂症，自闭症和情绪障碍。