Figure 4.

Effects of E₂ on reporter activity of a wild-type (WT) gad2 promoter construct or constructs with mutations of ERE sequences at −549, −711, and −1958 upstream of the gad2 translational start site (M-549, left column; M-711, middle column; and −1958, right column; for details, see Materials and Methods). Constructs were expressed in SN56.B5.G4 neural cells that were transiently transfected with empty vector (No ER, top row), hERα (second row), hERβ (third row), or both hERα and hERβ (ERαβ, bottom row). Cells were treated with 10 nm E₂ or ethanol vehicle (Veh) for 24 h before assaying reporter activity using dual-luciferase assays. The induction of promoter activity was expressed as fold activation compared with vehicle control. Each bar represents the mean ± SEM of values from at least nine independent samples. ^aSignificantly different from corresponding WT (p < 0.001); ^bsignificantly different from corresponding Veh control (p < 0.001); ^csignificantly different from corresponding Veh control (p < 0.01).