FIGURE 7.

EGF inhibition of α5β1 function is mediated by phosphorylation of FLNa. A and C, clonal cell lines expressing either WT-FLNa (A) or the mutant S2152A (Mut-FLNa) (C) were compared in fibronectin-based adhesion assays in the absence (black bars) or presence (white bars) of EGF (3 nm) as described in the legend to Fig. 1. Parental cells (A431) or clones (vector) expressing only pcDNA3 served as controls. Statistical analysis to determine significance was performed using Student's t test, **, p < 0.01; ***, p < 0.001. Error bars indicate S.D. of triplicate samples for one of three representative experiments. B and D, lysates from parental cells (A431), clonal cells expressing only pcDNA3 (vector), or clonal cell lines expressing either WT-FLNa (B) or the S2152A mutant (Mut-FLNa) (D) were immunoblotted for FLNa and FAK. FAK staining served as a loading control. Western blots are representative of three separate experiments.