Depletion of P-Rex1 suppresses glucose-induced membrane targeting of Rac1 in INS-1 832/13 cells. Panel A: INS-1 832/13 cells were transfected with con-si or P-Rex1-si and exposed to either low glucose (LG, 2.5 mM) or high glucose (HG, 20 mM) for 15 minutes. Following incubation, total membrane and cytosolic fractions were isolated using a commercially available kit (see Methods), and relative abundance of P-Rex1 and Rac1 was determined by Western blotting. Purity of the cytosol and membrane fractions was assessed by expression of GAPDH and E-Cadherin in those fractions, respectively. A representative blot from five independent studies is shown. Panel B: Densitometric analysis of relative abundance of Rac1 in the membrane fraction obtained from studies described in Panel A. Data are expressed as mean ± SD from three experiments. (* p< 0.05) Comparisons shown: a- significant compared with LG Con-si; b- significant compared with LG P-Rex1-si; c- significant compared with HG Con-si.