Alteration of the ligand-dependent association with transcriptional coregulators by mutant PML/RARα fusion proteins.

(A) Interaction of SMRT with wild-type and mutant PML/RARα proteins on a DR5 RARE in gel mobility shift assay. In vitro–translated PML/RARα fusion proteins were coincubated with the [³²P]-labeled DR5 RARE, along with bacterially expressed GST-SMRT-IDII in the presence of increasing concentrations of ATRA. The position of the complex shifted by SMRT is indicated. (B) Interaction of ACTR with wild-type and mutant PML/RARα proteins on a DR5 RARE in gel mobility shift assay. In vitro–translated PML/RARα fusion proteins were coincubated with the [³²P]-labeled DR5 RARE, along with bacterially expressed GST–ACTR-RID in the presence of increasing concentrations of ATRA. The position of the complex shifted by ACTR is indicated. (C) Interaction of mutant PML/RARα fusion proteins with the coactivator DRIP205 by GST pull-down analysis. In vitro–translated ³⁵S-labeled wild-type and mutant PML/RARα fusion proteins were incubated with bacterially expressed and purified GST-DRIP205 in the absence and in the presence of increasing concentrations of ATRA as indicated. GST alone was included as the negative control.