Cofilin / ADF Regulation in Rho GTPase Signaling

Rho GTPase 信号转导中的 Cofilin / ADF 调节

• 批准号: 7089020
• 负责人: GARY M BOKOCH
• 金额: $ 40.32万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7089020
• 关键词: actin binding protein; actins; cell motility; enzyme activity; enzyme induction /repression; enzyme mechanism; guanine nucleotide binding protein; guanosinetriphosphatases; immunologic assay /test; laboratory rabbit; microfilaments; phosphorylation; protein kinase; protein protein interaction; protein structure function; tissue /cell culture

DESCRIPTION (provided by applicant): Rho GTPases activated by upstream signals coordinate the cytoskeletal dynamics necessary for such complex motile processes as chemotaxis, metastasis, axon guidance, etc. One critical mechanism by which Rho GTPases control actin dynamics is via regulation of the action of cofilin/ADF family proteins. Cofilin/ADF (C/A) proteins act to sever F-actin filaments and promote F-actin depolymerization, both activities that are critical to the cytoskeletal rearrangements involved in formation of leading edge lamellae and cell motility. The action of C/A is regulated by phosphorylation/dephosphorylation of a critical regulatory site at Ser3. We have previously shown that Rac and Cdc42 regulate the phosphorylation and inactivation of C/A through the action of a downstream kinase cascade involving p21-activated kinase (PAK) and LIM kinase. We have now identified a unique phosphatase that acts to dephosphorylate and thus activate C/A. In combination with biochemical studies, we will utilize genetic means and RNA interference methodologies to disrupt phosphatase function in vivo. We propose to investigate the properties and regulation of this novel CA phosphatase in order to determine its importance in modulating cytoskeletal dynamic behavior. We have discovered regulatory interactions between Ser3-phosphoCA and 14-3-3 family proteins. We will investigate the hypothesis that, in addition to direct regulatory effects on CA, 14-3-3 proteins act as intermolecular scaffolds to link CA regulatory kinases and phosphatases into a coordinated regulatory module. Finally, we will investigate the coordinated action of the PAK1-LIMK-CA phosphatase-CA pathway during stimulated cell motility. Regulatory events modulating this signaling pathway will be determined. The question of localized vs. global regulation of CA function will be addressed by real time studies of the spatial and temporal dynamics of the signaling molecules involved. The proposed studies should give us unique information about the action of Rho GTPases to regulate CA function during cell motility.

描述（由申请人提供）： 由上游信号激活的Rho GTP酶协调细胞骨架动力学， Rho GTP酶控制肌动蛋白动力学的一个关键机制是通过调节cofilin/ADF家族蛋白的作用。Cofilin/ADF（C/A）蛋白作用于切断F-肌动蛋白丝并促进F-肌动蛋白解聚，这两种活性对于参与前缘膜形成和细胞运动的细胞骨架重排是关键的。C/A的作用受以下因素的调节： 在一个实施方案中，所述方法包括在Ser 3处的关键调节位点的磷酸化/去磷酸化。 我们以前已经表明，Rac和Cdc 42调节磷酸化和失活的C/A通过下游激酶级联反应，涉及p21激活激酶（PAK）和LIM激酶的行动。我们现在已经确定了一种独特的磷酸酶，它可以使C/A去磷酸化，从而激活C/A。结合生物化学研究，我们将利用遗传手段和RNA干扰方法来破坏体内磷酸酶功能。我们建议调查这种新的CA磷酸酶的性质和调节，以确定其在调节细胞骨架动力学行为的重要性。 我们已经发现Ser 3-phosphoCA和14-3-3家族蛋白之间的调节相互作用。我们将调查的假设，除了直接监管CA的影响，14-3-3蛋白作为分子间支架连接CA调节激酶和磷酸酶成一个协调的监管模块。最后，我们将研究PAK 1-LIMK-CA磷酸酶-CA途径在刺激细胞运动过程中的协调作用。将确定调节该信号通路的调节事件。CA功能的局部与全局调节的问题将通过对所涉及的信号分子的空间和时间动态的真实的时间研究来解决。拟议的研究应该给我们提供独特的信息Rho GTPases的行动，以调节CA功能在细胞运动。