FIG. 5.

(A) Activation of a Stat6-responsive reporter by the Stat6-ER chimera. U3A cells were transfected with the Stat6-selective mGɛx4-tk-luc reporter and either an empty expression vector (pcDNA3.1) or an expression vector for Stat6-ER plus a β-Gal control plasmid. Cells were left untreated or treated with estrogen (E2; 20 h) or IL-4 (5 h), lysed, and assayed for luciferase and β-Gal activities. (B) DNA sequence selectivity of the Stat6-ER chimera. U3A cells were transfected with an expression vector for Stat6-ER and either a Stat1-responsive reporter (IRF-1x4-tk-luc) or a Stat6-selective reporter (mGɛx4-pGL2) together with a β-Gal-expressing control plasmid. After transfection, cells were left untreated or treated with estrogen (E2; 20 h) or IL-4 (5 h), lysed, and assayed for luciferase and β-Gal activities. The normalized responses were calculated by dividing the luciferase value by the β-Gal value for each transfection. The data are presented as the mean of at least three independent experiments.