Fig. 8.

Binding of FXRα1 and FXRα2 to IR1a and IR1b in vitro. EMSAs were performed using (A) human hIR1a, (B) mouse/rat m/rIR1a, or (C) IR1b as probe. Nuclear extracts were prepared from Huh 7 cells transfected with FXRα1 or FXRα2. The specificity of the binding was established with competition assays using competing oligonucleotides, including unlabeled or mutated probe with 10× concentration. Identification of FXR protein in the shifted complex was carried out by supershift assays using polyclonal Abs against human FXR. The shifted bands representing the specific binding of FXR to the probe or FXR Abs to FXR/DNA complex are indicated by arrows.