Figure 1.

Cytoplasmic variants of ERα and ERβ display reversed activity at an AP-1 response element. (A) HC11 cells were transfected with expression vectors for ERα wt, NLSA, deleted in the hinge domain (Δ245-307), ERβ wt, ERβ Flag 148-530 or ERβ 148-530 Flag. The cellular localization of the receptor proteins was analysed by indirect immunofluorescence as described in Experimental Procedures. HC11 cells were transiently co-transfected with (B) 500 ng coll-73-luc reporter gene or (C) 1 μg β-casein reporter gene and 200 ng of ERα wt, NLSA, ERβ wt, ERβ Flag 148-530 or ERβ 148-530 Flag. Cells were treated with either no hormone (NH) or 10^-8 M 17β-estradiol (E2), and the reporter activity was analysed 24 hours after treatment. Luciferase activity was normalised using β-gal as an internal control. Data are representative of at least three independent experiments performed in duplicate. Mean and ± SD are shown.