Figure 9: PtdIns5P-induced localization of active Rac1 in dorsal ruffles and vesicles requires endocytosis.
From: Phosphatidylinositol 5-phosphate regulates invasion through binding and activation of Tiam1
(a) Control and IpgD-MEF-expressing Raichu-Rac1 were serum-starved for 2 h before the addition of 0.4 M sucrose for 2 more hours. Cells were fixed and imaged. The right panels represent higher magnifications of boxed areas on the larger image. Arrowheads indicate vesicles with active Rac1. Scale bar, 10 μm. (b) Changes in FRET were represented as a percentage of FRET in vesicles over FRET in the cytosol (called ‘control’) of indicated cells and treatment. (c) Similar representation as in (b) performed on the cell periphery (plasma membrane for all; plasma membrane and ruffles in the case of WT MEFs treated by PtdIns5P). (d) Similar representation as in (b) performed on the experiment described in (a).
