Figure 6

Treatment of HeLa cells with inhibitors of the EGF receptor (EGFR), FAK, and c-Src activation disrupts C. jejuni -dependent EGF receptor and caveolin-1 phosphorylation. HeLa cells were untreated or treated with inhibitors to FAK (5 μM TAE 226), EGFR (20 μM erlotinib), c-Src (10 μg/ml PP2), and both FAK and EGFR inhibitors, as indicated in the figure. Positive and negative controls consisted of C. jejuni infected and uninfected cells. Panels: A) Cell lysates were immunoprecipitated with either an EGFR antibody or a FAK antibody, separated by SDS-PAGE, and blotted for total EGFR (loading control), pEGFR, FAK, pFAK, and pCaveolin-1. Lanes: 1, Infected with C. jejuni in the absence of any inhibitor (vehicle only); 2, Treated with TAE 226 and infected with C. jejuni; 3, Treated with erlotinib and infected with C. jejuni; 4, Treated with PP2 and infected with C. jejuni; 5, Treated with both TAE 226 and erlotinib and infected with C. jejuni; 6, Uninfected cells (Cells only). Also shown are the blots of the IgG isotype control IP probed with caveolin-1, EGFR, and FAK antibodies. B) Quantitation of pEGFR and pCaveolin-1 from three independent experiments. The asterisk indicates P ≤ 0.05 as judged by one-way ANOVA followed by post-hoc Tukey’s analysis. Each error bar represents ± the standard deviation of the mean (SD). C) The data indicates that caveolin-1 is phosphorylated by c-Src, which is stimulated in response to the activation of FAK and the EGFR (Panel C).