Role of PAK5 in neurons and dendritic spines

PAK5 在神经元和树突棘中的作用

• 批准号: 6777735
• 负责人: AUDREY G MINDEN
• 金额: $ 32.58万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6777735
• 关键词: axon; cell morphology; cell motility; cerebellar Purkinje cell; dendrites; electromagnetic radiation; enzyme activity; enzyme mechanism; enzyme substrate; genetically modified animals; guanosinetriphosphatases; laboratory mouse; microscopy; neurogenesis; neuronal guidance; neurons; protein protein interaction; pyramidal cells; serine threonine protein kinase; transfection

DESCRIPTION (provided by applicant): The Rho GTPases Cdc42, Rac, and Rho regulate cell morphology by controlling the organization of the actin cytoskeleton. While they were originally characterized in fibroblasts, they also have key roles in neuronal development. For example, they play important roles in controlling axon guidance and neurite outgrowth. Our recent work has indicated that another function of the Rho GTPases may be to control the densities and morphologies of dendritic spines. Dendritic spines are actin rich projections found on the surface of most dendrites, and they mediate most synaptic contacts in the brain. The regulation of spine density, shape, and motility is thought to have important implications for the development and function of the neocortex. The targets for the Rho GTPases that mediate changes in neuronal cell morphology are not entirely known. We have identified a new target for Cdc42 and Rac called PAK5, which is a serine/threonine kinase that is expressed primarily in the brain. We have found that PAK5 triggers filopodia formation and neurite outgrowth in neuronal cell lines. The substrates for PAK5 are unknown. The goal of this proposal is to identify PAK5 targets and regulatory proteins and to determine whether and how PAK5 and its target proteins control neuronal morphology. In the first aim we will identify molecular targets for PAK5 and proteins that interact with PAK5. In the second aim we will determine whether these proteins are part of the pathway that leads to neurite outgrowth and filopodia formation in N1E-115 cells. In the third aim we will use biolistic transfections and two photon microscopy to investigate the possible role for PAK5 in regulating the morphology, density, and motility of dendritic spines in pyramidal neurons and purkinje cells from mouse brain slices. In this aim we will also examine spine motility and structure in PAK5 knockout mice that are being generated in our lab. Overall, the results from the experiments in this proposal will help elucidate the molecular mechanisms that control neuronal cell morphology and spinogenesis, which have important repercussion for the development and function of the normal and diseased brain.

描述（由申请人提供）： Rho GTPASE CDC42，RAC和RHO通过控制肌动蛋白细胞骨架的组织来调节细胞形态。尽管它们最初以成纤维细胞为特征，但它们在神经元发育中也具有关键作用。例如，它们在控制轴突引导和神经突生长中起着重要作用。我们最近的工作表明，Rho GTPases的另一个功能可能是控制树突棘的密度和形态。树突状棘是大多数树突表面发现的富肌动蛋白的投影，它们介导了大脑中大多数突触接触。脊柱密度，形状和运动的调节被认为对新皮层的发展和功能具有重要意义。介导神经元细胞形态变化的Rho GTPase的靶标并不完全清楚。我们已经确定了CDC42和RAC称为PAK5的新靶标，这是一种主要在大脑中表达的丝氨酸/苏氨酸激酶。我们发现PAK5触发了神经元细胞系中的丝状形成和神经突生长。 PAK5的底物未知。该建议的目的是确定PAK5靶标和调节蛋白，并确定PAK5及其靶蛋白是否控制神经元形态。在第一个目标中，我们将确定与PAK5相互作用的PAK5和蛋白质的分子靶标。在第二个目标中，我们将确定这些蛋白是否是导致N1E-115细胞中神经突生长和丝状形成的途径的一部分。在第三个目的中，我们将使用生物学转染和两个光子显微镜研究PAK5在调节锥体神经元中树突状棘的形态，密度和运动中的可能作用，而小鼠脑切片中的Purkinje细胞的可能作用。在此目标中，我们还将检查我们实验室中正在生成的PAK5敲除小鼠中的脊柱运动和结构。总体而言，该提案中实验的结果将有助于阐明控制神经元细胞形态和旋转发生的分子机制，这些机制对正常和患病大脑的发展和功能具有重要影响。