PDK1 and MRCKα regulate lamellipodia retraction upon EGF stimulation. (A) A representative MCF10A cell infected with a lentiviral vector coding for LifeAct-GFP, stimulated with EGF at t = 0 s, and imaged at different times before and after stimulation. Bar, 10 µm. (B) Time-lapse measurement of MCF10A electrical impedance in the presence or absence of EGF stimulation. Darker lines represent the mean values while lighter bands represent the area included between +SD and –SD. (C) Electrical impedance of MCF10A transduced with shScr, shPDK1 #79, or shPDK1 #81 upon EGF stimulation. (D and E) Protrusion and retraction slopes calculated from the electrical impedance. (F) Electrical impedance of MCF10A transduced with empty vector and PDK1_WT upon EGF stimulation. (G and H) Protrusion and retraction slopes calculated from the electrical impedance. Each error bar represents the mean and standard error of the mean of five independent experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001.