Fig. 4.

PIP3 modulates the membrane-association and -dissociation kinetics of PTEN. a A TIRF image of DdPTEN-Halo-TMR in a living cell expressing myrPI3K2 in the presence of 5 μM latrunculin A and 40 μM LY294002. b Trajectories of single DdPTEN molecules undergoing lateral diffusion on the cell membrane of myrPI3K2-expressing cells in the presence (upper, low PIP3) or absence (lower, high PIP3) of LY294002. Start and end positions are indicated by the magenta and green circles, respectively. Time, sec. c Dissociation curves of DdPTEN (circle), DdPTEN_G129E (inverted triangle) and HsPTEN (triangle) from the low (pale green) and high (dark green) PIP3 membranes. Lines represent fitting to equation (1). The data are represented as means, and statistics including the exact n values are summarized in Table 1. d Relative association frequencies of DdPTEN (n = 10 and 14 cells), DdPTEN_G129E (n = 12 and 7 cells) and HsPTEN (n = 15 and 15 cells) to the low (pale green) and high (dark green) PIP3 membranes, respectively. The actual data are calculated accordingly to the regression equation. Error bars, s.e. P = 0.085, 0.159, and 0.400 (low PIP3 vs. high PIP3 for DdPTEN, DdPTEN_G129E, and HsPTEN, respectively). P = 0.071 and 0.000 (DdPTEN versus DdPTEN_G129E and DdPTEN versus HsPTEN, respectively, under low PIP3 conditions). P values were obtained by regression slope test. Scale bars, 1 μm