Kindlin-2 phosphorylation by Src at Y193 enhances Src activity and is involved in Migfilin recruitment to the focal adhesions

Kindlin-2 regulates external to internal cell signaling by interaction with integrins in a process that involves the tyrosine kinase, Src. However, the underlying mechanisms remain elusive. Here we report that Src binds to and phosphorylates Kindlin-2 at Y193. Reciprocally, Kindlin-2-Y193 phosphorylation activates and maintains Src kinase activity. Kindlin-2-Y193 phosphorylation is also involved in its binding capacity with Migfilin and the recruitment of Migfilin to the focal adhesions. Functionally, we demonstrate that Kindlin-2-Y193 phosphorylation regulates Kindlin-2-mediated cell spreading and migration. These findings suggest that Src, Kindlin-2 and Migfilin together constitute a positive feedback loop that controls Src activity and regulates integrin-mediated cellular functions.