RARE binding by heterodimers of APL fusion proteins.

(A) Binding of heterodimers containing RXRα and STAT5b-RARα, PLZF-RARα, PML-RARα, or wild-type RARα to 2 RAREs, DR5G and DR5T. (B) STAT5b-RARα/RXRα heterodimer formation and RARE binding with increasing concentration of RXRα. In vitro translated STAT5b-RARα protein (2.0 μL) was incubated without or with in vitro translated RXRα protein (0, 0.05, 0.1, 0.2, 0.5, 1.0, and 2.5 μL). Gel-shift assays were performed using 2 RAREs, DR5G and DR5T. The location of the STAT5b-RARα homodimer band is indicated by the filled triangle; the location of the STAT5b-RARα/RXRα heterodimer composed of one molecule of STAT5b-RARα plus one molecule of RXRα is indicated by the unfilled triangle. The arrow indicates the position of the RXRα homodimer binding to DR5G. (C) STAT5b-RARα/RXRα heterodimer can bind a series of RAREs. STAT5b-RARα/RXRα heterodimer is indicated by the filled triangle; RXRα homodimer is indicated by the unfilled triangle.