Kinase activity of Src is primarily responsible for phosphorylating p130Cas in focal adhesion complexes with FAK. 293T cells were transfected and subjected to immunoprecipitation and probing as shown. Phosphorylation of p130Cas was absent (A) when Src lacked kinase activity (kd), but not (B) when FAK lacked kinase activity (kd), suggesting that the primary function of FAK is to hold p130Cas and Src in proximity to allow p130Cas phosphorylation by Src. Approximate position of the molecular weight markers is shown on left (in kDa).
Sharma and Mayer BMC Cell Biology 2008 9:50 doi:10.1186/1471-2121-9-50