Figure 4.

(A) RARE binding of various fusion proteins. PML–RARα and PLZF–RARα bound to DR5G in homodimers or in complexes with RXRα. NPM–RARα also bound to DR5G possibly in the form of homotetramer or in different complexes with RXRα. (B) Disappearance of shifted bands with increasing concentrations of cognate DR5G indicates high specificity of RARE binding. (C) Gel-shift analysis showed different ligand sensitivities in interactions with SMRT. Compared with the wild-type receptor, PML–RARα and NPM–RARα had decreased ligand sensitivities, whereas PLZF–RARα was insensitive to ATRA even at pharmacological concentrations. Solid arrows indicate high molecular mass receptor/SMRT complex, whereas open arrows point to receptors dissociated from SMRT. (D) GST–SMRT pull down confirmed the above result.