REGULATION OF NEUTROPHIL RECEPTOR/G PROTEIN INTERACTIONS

描述：化学引诱物和生长因子之间的通讯 受体和下游Rho家族小GTP酶启动细胞事件 对白细胞和成纤维细胞的运动反应很重要。 博士 Bokoch和他的同事将研究一种这样的受体调节的 途径，Rac/Cdc 42介导的靶蛋白Pak的活化 （p21活化激酶）。 拟议的研究涉及生物学 受体用于调节肌动蛋白细胞骨架的途径，并将 确定Pak活性控制的新机制。 在他们的第一个具体目标中，Pak通过分子相互作用 调节肌动蛋白细胞骨架将在结构上确定， 在明确定义的成纤维细胞模型系统中机械地。 巴基斯坦的域名 重要的细胞骨架调节将确定使用组合 分子和细胞的方法。 靶蛋白与 这些结构域将被分离和表征。 他们将把他们对Pak在细胞骨架调节方面的研究扩展到 第二个目标，这将评估一种新的GTP酶独立的机制， 调控 膜靶向激活Pak的分子基础 将被调查。 调查人员将研究 膜结合激活Pak参与神经突的细胞骨架调节 使用PC 12细胞作为模型系统的开发。 的作用 Pak结合Nck衔接蛋白在这个过程中也将被探测。 受体似乎通过不同于直接的机制来控制Pak活性。 通过Rac或Cdc 42激活，包括调节性去磷酸化 对Pak活化过程至关重要的反应。 因此，第三个目标将 专注于鉴定和纯化磷酸酶， 帕克利用分子和生物化学手段，他们将探索机制 磷酸酶控制Pak活性，并将启动对 这种调节性磷酸酶与受体介导的Pak的相关性 activation.

DESCRIPTION: Communication between chemoattractant and growth factor receptors and downstream Rho family small GTPases initiates cellular events important for the motile responses of leukocytes and fibroblasts. Dr. Bokoch and his colleagues will investigate one such receptor-regulated pathway, the Rac/Cdc42-mediated activation of the target protein Pak (p21-activated kinase). The proposed studies address the biological pathways used by receptors to regulate the actin cytoskeleton, and will identify novel mechanisms by which Pak activity is controlled. In their first specific aim, the molecular interactions through which Pak regulates the actin cytoskeleton will be determined structurally and mechanistically in a well-defined fibroblast model system. Domains in Pak important for cytoskeletal regulation will be identified using a combination of molecular and cellular approaches. Target proteins which interact with these domains will be isolated and characterized. They will extend their studies of cytoskeletal regulation by Pak in the second aim, which will evaluate a novel GTPase-independent mechanism for Pak regulation. The molecular basis for Pak activation by membrane targeting will be investigated. The investigators will examine the significance of Pak activation by membrane association in cytoskeletal regulation of neurite development using the PC12 cell as a model system. The role of the Pak-binding Nck adapter protein in this process will also be probed. Receptors appear to control Pak activity by mechanisms distinct from direct activation via Rac or Cdc42 which include regulatory dephosphorylation reactions critical to the Pak activation process. The third aim will thus focus upon identification and purification of phosphatases that act upon Pak. Using molecular and biochemical means, they will probe the mechanisms by which phosphatases control Pak activity, and will initiate studies on the relevance of such regulatory phosphatases to receptor-mediated Pak activation.