Figure 7.

PRL induces STAT5 binding to a consensus sequence on the rat FoxO1 promoter. Nuclear proteins were prepared from INS-1 cells treated with PRL (20 nm) or diluent for 30 min. The proteins were incubated with radiolabeled double stranded oligonucleotides encoding STAT5 consensus sequences in the rat β-casein promoter or the rat FoxO1 promoter (Fig. 6A). Parallel incubations contained a 200-fold excess of cold competitor (CC) double-stranded oligonucleotides encoding the STAT5 sequence in the rat β-casein gene or 2 μg of polyclonal anti-STAT5a antibody (Ab, Fig. 6B). The protein-DNA complexes were separated by PAGE. The shifted bands (arrow) represent binding of STAT5 to DNA. The arrowhead (Fig. 6B) represents the supershifted complex.