Figure 2

Activation of ZFP36 promoter upon EGF stimulation. (A) MCF-7 or HEK293 cells were transfected with reporter vector containing full-length ZFP36 promoter fragment (-488 to +905 bp) and, where indicated, with ELK-1 expression vector (pExpELK-1). 24 hrs after transfection cells were stimulated for 8 hrs with EGF with or without U0126 pretreatment and then luciferase activity was measured. (B) Serum-starved MCF-7 cells were stimulated with EGF (20 ng/ml) for indicated times, harvested and subjected to Western blot analysis (with anti-phospho ELK-1 and anti-GAPDH antibodies as loading control). Asterisk indicates unspecific band (C) The total cellular proteins from different cell lines were isolated and subjected to Western blot analysis (with anti-ELK-1 antibody and anti-GAPDH antibodies as loading control). (D) MCF-7 cells were co-transfected with reporter vector containing full-length ZFP36 promoter fragment (-488 to +905 bp) and indicated amounts of pElk-EN or pElk-VP16. 24 hrs after transfection luciferase activity was measured. (A and D) Representative results from three independent experiments are shown and plotted as means ± SD (n = 3)