FIGURE 6.

PARP1 is an indispensable component of ERα-ERE complex. A and B, binding of ERα to ERE was detected by EMSA (A) and Southwestern blot assay (B). VSMCs were transfected with PARP1 siRNA (50 nm) or unrelated siRNA (50 nm) for 48 h, followed by treatment with estradiol (E, 10⁻⁷ m, 24 h). C, binding of ERα to ERE was detected by EMSA assay. Nuclear extracts from non-treated VSMCs were incubated with PARP1 protein or IgG (served as negative control). Incubation of nuclear extracts with anti-ERα Ab showed the specificity of the ERα-ERE complex band. D, in a cell-free system, recombinant ERα protein was incubated with vehicles, PARP1 protein, or IgG (served as negative control), respectively. The binding of ERα to ERE was detected by EMSA assay. Results are from three independent experiments.