Integrin-mediated adhesion regulates cellular responses to changes in the mechanical and biochemical properties of the extracellular matrix. Cell-matrix adhesion regulates caveolar endocytosis, dependent on caveolin 1 (Cav1) Tyr14-phosphorylation (pY14Cav1), to control anchorage-dependent signaling. We find that cell-matrix adhesion regulates pY14Cav1 levels in mouse fibroblasts. Biochemical fractionation reveals endogenous pY14Cav1 to be present in caveolae and focal adhesions. Adhesion does not affect caveolar pY14Cav1, supporting its regulation at focal adhesions, which PF-228-mediated inhibition of focal adhesion kinase (FAK) disrupts. Cell adhesion on 2D-polyacrylamide matrices of increasing stiffness stimulates Cav1 phosphorylation, which is comparable to the phosphorylation of FAK. Inhibition of FAK across varying stiffnesses shows it regulates pY14Cav1 more prominently at higher stiffness. Taken together, these studies reveal the presence of FAK-pY14Cav1 crosstalk at focal adhesions, which is regulated by cell-matrix adhesion.

中文翻译：

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粘附依赖的 Caveolin1 Tyrosine-14 磷酸化受 FAK 调节以响应基质刚度的变化

整合素介导的粘附调节细胞对细胞外基质机械和生化特性变化的反应。细胞基质粘附调节小窝内吞作用，依赖于小窝蛋白 1 (Cav1) Tyr14 磷酸化 (pY14Cav1)，以控制依赖锚定的信号传导。我们发现细胞基质粘附调节小鼠成纤维细胞中的 pY14Cav1 水平。生化分级显示内源性 pY14Cav1 存在于小窝和粘着斑中。粘附不影响小窝 pY14Cav1，支持其对粘着斑的调节，PF-228 介导的粘着斑激酶 (FAK) 抑制会破坏粘着斑。增加刚度的二维聚丙烯酰胺基质上的细胞粘附刺激 Cav1 磷酸化，这与 FAK 的磷酸化相当。FAK 对不同刚度的抑制表明它在更高的刚度下更显着地调节 pY14Cav1。总之，这些研究揭示了在粘着斑处存在 FAK-pY14Cav1 串扰，这是由细胞基质粘附调节的。