Stimulation of cell migration by overexpression of focal adhesion kinase and its association with Src and Fyn

Open Access
Publisher Website
Google Scholar
Abstract
Cellular interactions with the extracellular matrix proteins play important roles in a variety of biological processes. Recent studies suggest that integrin-mediated cell-matrix interaction can transduce biochemical signals across the plasma membrane to regulate cellular functions such as proliferation, differentiation and migration. These studies have implicated a critical role of focal adhesion kinase (FAK) in integrin-mediated signal transduction pathways. We report here that overexpression of FAK in CHO cells increased their migration on fibronectin. A mutation of the major autophosphorylation site Y397 in FAK abolished its ability to stimulate cell migration, while phosphorylation of Y397 in a kinase-defective FAK by endogenous FAK led to increased migration. We also find that the wild-type and the kinase-defective FAK were associated with Src and Fyn in CHO cells whereas the F397 mutant was not. These results directly demonstrate a functional role for FAK in integrin signaling leading to cell migration. They also provide evidence for the functional significance of FAK/Src complex formation in vivo.