Figure 7.

Synergistic activation of Nur77 promoter activity by β-catenin and AP-1. A, B) Effect of β-catenin and AP-1. HEK293T cells were cotransfected with pNur77 (A) or pAP-1 (B) reporter gene together with expression vectors for c-Fos, c-Jun, and β-catenin as indicated. Cells were then treated with vehicle or 10 μM DCA for 20 h and assayed for reporter activity. β-Galactosidase expression vector was also included in each transfection. Relative luciferase activity was normalized to β-galactosidase activity. C) Interaction of endogenous β-catenin with c-Fos and c-Jun. Lysates from SW480 cells treated with vehicle or 10 μM DCA were analyzed by coimmunoprecipitation assays using anti-β-catenin antibody or control IgG. Immunoprecipitates were immunoblotted using antibodies for c-Fos, c-Jun, and β-catenin. D, E) Interaction of transfected β-catenin and AP-1. HEK293T cells transfected with HA-β-catenin, c-Fos, and c-Jun were subjected to 10 μM DCA treatment for 3 h. Lysates were immunoprecipitated with either anti-HA (D), anti-c-Jun or anti-c-Fos (E) antibodies. IgG served as control in each coimmunoprecipitation.