FIGURE 4.
Enhancement of protein binding to the G−172 → T region, and of transcriptional activity in MOR gene by PARP-1 overexpression. A, PARP-1 overexpression was shown in Western blotting. B, PARP-1 binding to the T−172 probe was investigated in EMSA. HEK293T cells were transfected with the PARP-1 expression vector, and a nuclear extract was prepared for EMSA 48 h after the transfection. C, transcriptional activity in luciferase assay with pGL3T−172 TK or pGL3T−172. HEK293T cells were transfected with the PARP-1 expression vector and respective reporter vector, and cell lysate was prepared for luciferase assay 48 h after the transfection. The error bar indicates S.D. derived from three independent experiments. β-Galactosidase activities, a control for transfection efficiency, were used to normalize the data. The asterisks indicate significant difference (***, p < 0.001). I.B., immunoblotting.