Fig. 1

The PP2A switch-related interactions and phosphorylations are modulated by PKC inhibition. A, B Effect of PKC inhibition on PP2A switch-induced interactions. αT3-1 (A) or PC3 (B) cells were transfected with HA-PP2Ac (in PCDNA3) in serum-starvation medium (0.1% FCS, 16 h). The cells were then pretreated with PKC inhibitor GFx (3 µM, 20 min) or DMSO (control) and then were either stimulated with TPA (250 nM, 30 min) or left untreated. The cells were then harvested, and PP2Ac was IPed with anti-HA Ab. The Co-IPed PI3K, AKT and IGBP1 as well as the IPed HA-PP2Ac were detected by Western blotting with the relevant Abs. The bar-graphs in the lower panels represent means ± standard deviation (SD) of three experiments. Significance of change from DMSO, non-stimulated (-) control is calculated. * p < 0.01, ** p < 0.05. C, D Effect of PKC inhibitors on PP2A switch-induced phosphorylations. αT3-1 (C) or PC3 (D) cells were serum-starved (0.1% FCS, 16 h). The cells were then pretreated with PKC inhibitor GFx (3 µM, 20 min) or DMSO (control) and then either stimulated with TPA (250 nM, 30 min) or left untreated. Cells were harvested and the extracts were analyzed by Western blotting with the indicated Abs. The bar-graphs in the lower panels represent means ± SD of 3 experiments. Significance of change from DMSO, non-stimulated control (-) is calculated. * p < 0.01, ** p < 0.05