Fig. 3. Intact DBD domain in RXR is responsible for NES function. (A) Schematic representation of RXR and its mutants. (B) Subcellular localization of RXR mutants. RXR and its mutants were fused to GFP, then transfected into NIH3T3 cells. After transfection, cells were stained with Hoechst 33258 to visualize nuclei. Localizations of GFP-RXR protein and its mutants were visualized using fluorescent microscope. (C) Shuttling behavior of RXR and its different mutants. GFP-RXR and different GFP-RXR mutants were separately transfected into NIH3T3 cells as indicated, then fused with HeLa cells. The heterokaryons were visualized as described in Fig. 1A. Arrows indicate HeLa nuclei.