Regulation of cell motility by Arg tyrosine kinase

描述(由申请人提供)：了解调节细胞形状和运动的分子机制对于治疗神经疾病至关重要。一些疾病，如精神分裂症和癫痫，与突触功能和神经元形态的缺陷有关。ABL家族非受体酪氨酸激酶(Abl和Arg)是发育中的神经系统正常的细胞形态发生、成年小鼠脑内突触功能和神经元形态所必需的。这些过程依赖于基于肌动蛋白的细胞骨架的戏剧性重组。Arg含有两个不同的F-肌动蛋白结合域。它利用这些结构域在体外捆绑肌动蛋白细丝，并在成纤维细胞的脂板层诱导形成富含肌动蛋白的结构。这些激酶可能通过控制肌动蛋白细胞骨架来影响神经元和/或突触的形态和运动。这里提出的实验将研究Arg的肌动蛋白结合和捆绑能力如何调节细胞运动和生长因子诱导的肌动蛋白细胞骨架的重排。第一个目的是建立一种利用精氨酸黄色荧光融合蛋白重组的ABL-/-Arg-/-成纤维细胞来测量Arg在细胞中的定位和运动的系统。第二个目的是测量依赖Arg的细胞运动性的变化，并确定Arg对运动性的调节是依赖于激酶活性还是依赖于肌动蛋白结合和捆绑活性。第三个目的是研究Arg结合和捆绑肌动蛋白的能力是否在生长因子刺激导致的细胞骨架重排中发挥作用。这些研究应该有助于更好地理解肌动蛋白细胞骨架的变化如何调节正常神经元的形态、运动和功能，以及这种调节如何在神经系统疾病中被破坏。

DESCRIPTION (provided by applicant): Understanding the molecular mechanisms that regulate cell shape and motility is essential for treatment of neurological diseases. Several diseases such as schizophrenia and epilepsy are associated with defects in synaptic function and neuronal morphology. Abl family nonreceptor tyrosine kinases (Abl and Arg) are necessary for proper cellular morphogenesis in the developing nervous system and for synaptic function and neuronal morphology in the adult mouse brain. These processes depend on dramatic reorganizations of the actin-based cytoskeleton. Arg harbors two distinct F-actin-binding domains. It uses these domains to bundle actin filaments in vitro and to induce the formation of actin-rich structures at the lamellipodia of fibroblasts. These kinases may influence neuronal and/or synaptic morphology and motility by controlling the actin cytoskeleton. The experiments proposed here will investigate how Arg's actin-binding and bundling abilities regulate cell motility and growth factor-induced rearrangements of the actin cytoskeleton. The first aim is to establish a system for measuring Arg's localization and movement in cells using abl-/-arg-/-fibroblasts reconstituted with an Arg-yellow fluorescent fusion protein. The second aim is to measure Arg-dependent changes in cell motility and to determine whether Arg's regulation of motility is dependent on kinase activity or actin-binding and bundling activity. The third aim is to examine whether Arg's ability to bind and bundle actin plays a role in the cytoskeletal rearrangements that result from growth factor stimulation. These studies should lead to a better understanding of how actin cytoskeletal changes regulate neuronal morphology, motility, and function in normal neurons and how this regulation breaks down in neurological diseases.