Fig. 4.

PTEN posterior membrane translocation proceeded that of myosin and the electrotactic response of the cells. EFs were applied at time zero in all experiments. a Time-lapse analysis of fluorescence intensity ratio comparing GFP translocation toward posterior vs anterior plasma membrane in EF. The asymmetric redistribution of myosin II-GFP (blue line) showed significant delay compared to that of PTEN-GFP (red line). Such asymmetric relocalization was fully abolished in pten⁻ cells (orange line). EF triggered a sharp shortening of the average pseudopod length at the posterior region (green line), while increased that at the anterior of the electrotaxing WT cells (black line). b Time-lapse analysis of the directional migration of WT (red line) and pten⁻ cells (blue line). EF = 10 V/cm. c-f Comparison of the re-establishment of the PTEN-GFP and myosin II-GFP posterior membrane translocation post latrunculin A washout in EF. g Time-lapse analysis of fluorescence intensity ratio comparing GFP translocation toward posterior vs anterior plasma membrane post latrunculin A washout in EF. The asymmetric redistribution of PTEN-GFP (red line) preceded that of myosin II-GFP (blue line). EF triggered elongation of the average pseudopod length was re-established at the anterior region (black line), but not at the posterior region of the cells (green line). h Membrane fraction cell lysates from the cells treated with the indicated duration of EFs were analyzed by immunoblotting with antibodies against plasma membrane fraction of myosin II. i Band intensity was quantified (n ≥ 3)