FIG. 7.

βFtz-F1 enhances the 20E-dependent interactions between EcR/USP and FISC. (A) Schematic diagram of EcRb, USPb, βFtz-F1, and FISC. (B to D) Protein interactions were tested in a mammalian two-hybrid system. CV-1 cells were transfected with 5× UAS-TATA-Luc reporter construct, along with expression vectors for GAL4 and VP16 fusions, and full-length USPb and βFtz-F1 proteins, as indicated. After transfection, cells were cultured in medium with or without 1 × 10⁻⁶ M 20E. Data represent ratios of firefly luciferase to Renilla luciferase activity (relative luciferase activity), and the values shown are the means from three independent experiments, with error bars representing the standard deviations of the means. For EcRΔAF2, the AF2 core was removed from GAL4-EcR^348-675. DBD, DNA-binding domain; LBD, ligand-binding domain; CM, control medium.