FOCAL ADHESION TYROSINE KINASES AND CELL SIGNALING

本修订项目的长期目标是了解 由细胞受体介导的细胞信号事件， 识别细胞外基质和/或其它细胞的成分 表面分子 我们将特别关注酪氨酸的作用 磷酸化在调节这些途径，寻求定义 酪氨酸激酶的分子机制， 调控这些途径。 拟议的实验建立 并扩大过去四年取得的进展。 我们有 鉴定了一种新的蛋白酪氨酸激酶， 细胞粘着斑，命名为粘着斑激酶，FAK。 来自我们自己实验室和其他实验室的证据表明，FAK 在调节由相互作用引发的信号事件中起作用 整合素与细胞外基质的结合。 此外，我们自己的 研究表明，在src中FAK与pp 60 src稳定结合， 转化细胞 我们提出三个具体目标：第一， 定义和表征导致FAK激活的机制， 对整合素与确定的细胞外配体接合的应答。 这些研究将包括分析FAK与 特异性整合素的胞质结构域和局灶性整合素的组分 粘附以及可能与蛋白质的功能相互作用， 调节有丝分裂原和激素激活的信号转导通路。 第二，我们将研究FAK在监管 细胞局灶性粘连的形成和/或破坏， 其他细胞活动（例如，粘附，细胞铺展，细胞 迁移）和第二信使途径的可能控制。 在 在这些研究中，我们将调查表型和生化 表达变异FAK蛋白的细胞的特性，并试图 将已知的FAK活性缺陷与细胞内 新陈代谢. 最后，我们将描述函数的相互作用 在src转化细胞中FAK和pp 60 src之间的关系，并扩展了这一范例 FAK与pp 60 src或其他src可能的相互作用的分析 正常细胞中的激酶家族。 这些实验试图描绘出 pp 60 src在粘连灶结构紊乱中的作用 转化的细胞，并探讨FAK调节或 在正常细胞中由SRC家族激酶调节。

The long term goals of this revised project are to understand the nature of cellular signalling events mediated by cellular receptors that recognize components of the extracellular matrix and/or other cell surface molecules. We will focus specifically on the role of tyrosine phosphorylation in regulating these pathways, seeking to define the molecular mechanisms by which tyrosine kinases contribute to the regulation and control of such pathways. The proposed experiments build and extend the progress made during the past four years. We have identified a novel protein tyrosine kinase, that is associated with cellular focal adhesions, designated Focal Adhesion Kinase, FAK. Evidence from our own laboratory as well as other has indicated that FAK plays a role in regulating signalling events initiated by interactions of surface integrins with extracellular matrix. In addition, our own studies have demonstrated a stable association of FAK with pp60src in src transformed cells. We outline three specific aims: First, we will define and characterize the mechanisms that lead to activation of FAK in response to engagement of integrins with defined extracellular ligands. These studies will include an analysis of the interaction of FAK with cytoplasmic domains of specific integrins and components of focal adhesions as well as possible functional interactions with proteins that regulate mitogen and hormone activated signal transduction pathways. Second, we will examine the role of FAK in the regulation of the formation and/or breakdown of cellular focal adhesions, in the regulation of other cellular activities (e.g., adhesion, cell spreading, cell migration) and the possible control of second messenger pathways. In these studies we will investigate the phenotypic and biochemical properties of cells expressing variant FAK proteins and attempt to correlate known defects in FAK activity with alterations in cellular metabolism. Finally, we will characterize the function interactions between FAK and pp60src in src transformed cells and extend this paradigm to the analysis of possible interactions of FAK and pp60src or other src family kinases in normal cells. These experiments seek to delineate the role of pp60src in the structural perturbation of focal adhesions in transformed cells and explore the possibility that FAK regulates or is regulated by src family kinases in normal cells.