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: 7351814
• 负责人: William Daniel Bradley
• 金额: $ 2.53万
• 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/7351814
• 关键词: Actomyosin; Adhesions; Affect; Autistic Disorder; Axon; Biosensor; Brain; Cell membrane; Cells; Cellular Morphology; Class; Cues; Cytoskeleton; Dendrites; Development; Disease; Disruption; 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; Localized; Maintenance; Mediating; Mental disorders; Monitor; Mood Disorders; Morphogenesis; Morphology; Neurites; Neurons; Numbers; 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）：人脑的正常功能需要在整个成年期的发育和维持过程中进行精确调节。为了使神经元正常发挥作用并发出信号，它们之间的突触接触是通过响应环境线索而生长和分支的轴突和树突来实现的。许多精神疾病，例如精神分裂症、自闭症和情绪障碍，表现出神经元之间连接的减少和异常。 RhoA GTPase (Rho) 是细胞骨架的重要调节因子，其活性的变化会导致轴突和树突的连接延伸和收缩的改变。 Rho 活性是通过激活鸟嘌呤核苷酸交换因子 (GEF) 和抑制性 GTP 酶激活蛋白 (GAP) 来控制的。 p190RhoGAP (p190) 是此类调节因子之一，在抑制 Rho 和防止神经突回缩以及可能维持突触完整性方面发挥着关键作用。 p190 被非受体酪氨酸激酶 Arg（Abl 相关基因）磷酸化并激活，以响应整合素介导的粘附。 Arg 在神经元维持中也发挥着至关重要的作用，因为缺乏 Arg 的神经元表现会减少树突数量和分支的急剧减少。尽管有相关证据将 Arg、p190 和 Rho 与神经元结构和功能联系起来，但很少有与这些蛋白质直接相关的机制细节。我在此提出的实验将揭示 Arg 介导的 p190 对 Rho 的抑制与成纤维细胞和神经元的细胞骨架和形态变化之间的联系途径。在第一个目标中，我将定义响应整合素介导的粘附而激活精氨酸的机制。在第二个目标中，我将开发观察 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需的探针，这些变化是直接关联该通路中这些事件所必需的。在第三个目标中，使用目标 2 中开发的探针，我将同时监测 p190 的局部活性及其对 Rho 的抑制如何影响成纤维细胞和神经元的细胞骨架和形态动力学。这些研究将共同​​提供与 Arg 介导的 p190 对 Rho 的抑制与细胞骨架和细胞形态的变化相关的急需的机制细节。这将提供证据强调 Arg、p190 和 Rho 在神经元形态的维持和破坏中发挥的作用。长期目标是揭示操纵 Rho 活性的新策略，以防止其失调对树突结构产生有害影响，以期预防或治疗精神疾病，如精神分裂症、自闭症和情绪障碍。