A FAK/Src chimera with gain-of-function properties promotes formation of large peripheral adhesions associated with dynamic actin assembly.
A FAK/Src chimera with gain-of-function properties promotes formation of large peripheral adhesions associated with dynamic actin assembly.
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DOI：
10.1002/cm.20241
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发表时间：
2008
影响因子：
--
通讯作者：
P. F. Siesser;Leslie M. Meenderink;L. Ryzhova;K. E. Michael;D. Dumbauld;Andrés J. García;I. Kaverina
中科院分区：
文献类型：
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作者：
P. F. Siesser;Leslie M. Meenderink;L. Ryzhova;K. E. Michael;D. Dumbauld;Andrés J. García;I. Kaverina
酪氨酸激酶 FAK 和 Src 之间复合物的形成是整合素介导的关键信号传导事件，与细胞运动、存活和增殖有关。过去的研究表明，FAK 在复合物中的功能主要是作为“支架”，起到招募和激活细胞/基质粘附内的 Src 的作用。为了研究 FAK 相关 Src 信号传导对细胞的影响，我们开发了一种新的功能获得方法，该方法涉及表达 FAK 激酶结构域被 Src 激酶结构域取代的嵌合蛋白。这种 FAK/Src 嵌合体受到粘附依赖性激活，并促进 p130Cas 和桩蛋白的酪氨酸磷酸化达到比野生型 FAK 更高的稳态水平。当在 FAK -/- 小鼠胚胎成纤维细胞中表达时，FAK/Src 嵌合体产生了惊人的细胞表型，其特征是异常大的外周粘附、增强的粘附强度和大大降低的运动性。表达嵌合体的 FAK -/- 细胞的活细胞成像提供了证据，表明大的外周粘附与对 Src 选择性抑制剂敏感的动态肌动蛋白组装过程相关。这些发现表明 FAK 相关的 Src 激酶活性能够促进粘附完整性和肌动蛋白组装。
Formation of a complex between the tyrosine kinases FAK and Src is a key integrin-mediated signaling event implicated in cell motility, survival, and proliferation. Past studies indicate that FAK functions in the complex primarily as a "scaffold," acting to recruit and activate Src within cell/matrix adhesions. To study the cellular impact of FAK-associated Src signaling we developed a novel gain-of-function approach that involves expressing a chimeric protein with the FAK kinase domain replaced by the Src kinase domain. This FAK/Src chimera is subject to adhesion-dependent activation and promotes tyrosine phosphorylation of p130Cas and paxillin to higher steady-state levels than is achieved by wild-type FAK. When expressed in FAK -/- mouse embryo fibroblasts, the FAK/Src chimera resulted in a striking cellular phenotype characterized by unusual large peripheral adhesions, enhanced adhesive strength, and greatly reduced motility. Live cell imaging of the chimera-expressing FAK -/- cells provided evidence that the large peripheral adhesions are associated with a dynamic actin assembly process that is sensitive to a Src-selective inhibitor. These findings suggest that FAK-associated Src kinase activity has the capacity to promote adhesion integrity and actin assembly.