Figure 4
Local PA-Rac1 activation recruits the PBD of Pak1 and induces PI(4,5)P2 production.
(a) Recruitment of the Citrine-p21-binding domain (PBD) of Pak1 to the photoactivated region. RAW264 cells were co-transfected with pTriEx/mCherry-PA-Rac1 and pCitrine-PBD. The laser-irradiated area is indicated with a blue rectangle. The selected time-lapse images of phase-contrast, mCherry-PA-Rac1(red) and Citrine-PBD (signal intensity is shown by spectrum colour), captured at the indicated times were shown. Time 0 indicates the initiation of photoactivation. The bar indicates 10 μm. (b) The level of PI(4,5)P2 was locally increased in the region where membrane ruffles and pre-macropinosomes were formed during photoactivation. RAW 264 cells were co-transfected with pTriEx/mCherry-PA-Rac1 and pYFP-PLC-δ1 PH. The selected time-lapse images of phase-contrast, mCherry-PA-Rac1 (red),YFP-PLC-δ1 PH (green) and merged images captured at the indicated times were shown. The laser-irradiated area is indicated with a blue rectangle. Time 0 indicates the initiation of photoactivation. The bar indicates 5 μm.
