Figure 11. Pertussis toxin attenuates translocation of Rac1 and IQGAP1 to cell periphery induced by S1P or by silencing of S1PL.

HPAECs (∼50% confluence) grown on cover slips were transfected with either scrambled siRNA or S1PL siRNA (50 nM, 72 h), then treated with Pertussis toxin (100 ng/ml) for 16 h in 2% FBS in EBM-2 without growth factors. Cells were stimulated with 0.1% BSA-complexed S1P (1.0 µM) for 5 min, washed, fixed, permeabilized, probed with anti-Rac1 (A) or anti-IQGAP1 (B) antibodies, and examined by immunofluorescence microscopy using a ×60 oil objective.