FIGURE 3:

PKL is required for fibronectin- and EGF-dependent phosphorylation and activation of endogenous Vav2. HT1080 cells were spread on PL or Fibronectin FN in the absence (A) or presence (B) of EGF for the time periods indicated. FN alone was unable to induce phosphorylation of immunoprecipitated Vav2 (A), whereas elevated phosphorylation of Vav2 was observed when cells were spread on FN in the presence of 30 ng/ml EGF. (C) PKL coimmunoprecipitates with Vav2 when cells are spread on FN in the presence of EGF but not in the absence of EGF. (D) PKL knockdown by RNAi inhibits the stimulation of Vav2 phosphorylation in response to FN and EGF.