Figure 3

<div><p><b>Cortactin is not involved in EHEC-L-induced MPC.</b></p> <p>(A) Representative IB and quantitative data show that treatment of T84 cells with EHEC-L does not affect the phosphorylation of cortactin (p-cortactin) in contrast to EHEC infection, which almost completely dephosphorylates cortactin (* p = 0.0006); n = 6 monolayers from 3 independent experiments). (B) Representative XY confocal optical sections through the apical region of T84 cells show that p-cortactin (red) is absent from the apical macropinocytic blebs detected by F-actin (green), but is present in surrounding cells not involved in MPC similar to that in control conditions. Analysis of 27 apical macropinocytic blebs in EHEC-L treated cells from 3 independent preparations showed no presence of p-cortactin in F-actin blebs. Also, p-cortactin is virtually absent from EHEC infected T84 monolayers. In both panels: p-cortactin – red by AlexaFluor568; F-actin – green by phalloidin-AlexaFluor488; nuclei – blue by Hoechst.</p>