Expression of Stat5 in transfected FdCP1 cells.

Nuclear extracts were prepared as outlined in Figure 1 and sequentially immunoblotted with a FLAG epitope-tagged specific antibody (A), a Stat5 phospho-specific antibody (B), and a pan–Stat5-specific antibody (C). Recombinant inactive FLAG-Stat5b (rFLAG-Stat5b) was included as a control (lane 11). Matched cytoplasmic extracts are evaluated in D. The mobility of full length (ie, p94/p96) and truncated (ie, p77/p80) Stat5a and Stat5b are indicated in the left margin of each panel. 19-neo (lanes 1, 2) and 19-WT (lanes 3, 4) are clones of cells stably transfected with pSV2-neo and FLAG-Stat5b^WT, respectively. 19-M1 (lanes 5, 6) and 19-M2 (lanes 7, 8) are 2 independent clones of cells transfected with FLAG-Stat5b^m/m.