Fig. 6.

Ser₂₃₂ and thr₂₃₁ phosphorylation modulate Pdx-1 transcriptional activity. HEK293T cells seeded in a six-well plate were transfected with 2 μg of empty vector (pcDNA3) or pcDNA3-derived vectors encoding either wild type or mutant Pdx-1, 1.5 μg of RIP luciferase, and 0.5 μg of β-galactosidase by calcium phosphate transfection methods. The cells were lysed, and luciferase activity was measured 48 h after transfection. The data between the control cells (empty vector group) and the Pdx-1 wild type-expressing cells (a) are expressed as the ratio of the RIP luciferase activity/β-galactosidase activity. On the contrary, results between Pdx-1 WT and different mutant-expressing cells (b) are shown as RIP luciferase activity divided by the amount of Pdx-1 proteins expressed in the cells. In both cases, the relative activity in Pdx-1 wild type-expressing cells was set at 100%. The results are the means ± SE of three separate experiments done in triplicate