Stat5 associates with RXR-RAR in an IL-3–dependent manner.

(A) Cellular lysates (2 mg) of BAF3 cells that had been stably transduced with a FLAG-tagged RXR cDNA (BaF3-RXR cells) were immunoprecipitated with either Stat5 antibody (lane 3) or control IgG (lane 2). The immunoprecipitates, as well as total cell lysate (50 μg; lane 1) were then subjected to Western blot analysis with the indicated antibodies. (B,C) BaF3-RXR cells were deprived of IL-3 for 24 hours and following the addition of IL-3 (5 ng/mL), cell extracts were harvested at the indicated time points. These extracts (1 mg) were immunoprecipitated with antibodies to (B) Stat 5 and (C) RXRα, and the immunoprecipitates were subjected to Western blot analysis with the indicated antibodies.