The PAR complex is involved in Tiam1 targeting to adhesions and in signaling from integrin. (A) Cells were treated with 40 µM aPKC inhibitor for 1 h before fixation and stained with talin (green) and Tiam1 (red) antibodies. The insets in the left panels are magnified in the right panels. Bars, 10 µm. (B) Cells transfected with the indicated siRNAs were stained with talin (green) and Tiam1 (red) antibodies. Bars, 10 µm. (C) Cells transfected with PAR3 siRNAs and the indicated plasmids were stained with GFP (green) and Tiam1 or talin (red) antibodies. Bars, 10 µm. Bar graphs below (A) or to the right (B and C) of the corresponding images represent the number of talin- or Tiam1-containing adhesions per 100 µm². (D) Adhesion-induced Rac1 activation in PAR complex–depleted cells. Depletion of the PAR complex attenuated Rac1 activation. The graph to the right quantifies Rac1 activation in these cells. Bars in the graph represent means ± SD. (E) Images of PAR complex–depleted cells at 2 h after spreading on FN. The cells were stained with anti-GFP antibody (green) and phalloidin (red). Bar, 10 µm. The bottom graph quantifies cell area after spreading. Data represent the means ± SD of at least three independent experiments. n > 50. *, P < 0.05; **, P < 0.01 versus respective control cells (A, B, and C, Tukey’s HSD; D and E, Student’s t test). Results are representative of more than three experiments.