PNU156804 inhibits IL-2–inducible Tyr phosphorylation of Stat5a/b in human T cells.

PHA-activated human T cells were pretreated with DMSO, 10 μM in active analogue PNU159744, or 10 μM PNU156804 for 16 hours and then stimulated for 10 minutes with (+) or without (−) 100 nM IL-2 for 10 minutes at 37°C. Cells were lysed and immunoprecipitated with anti-Stat5a (A) or anti-Stat5b (B) and were blotted with monoclonal antiphosphotyrosine Stat5 (Y701, upper panel), polyclonal phosphoserine Stat5 (S726-Stat5a or S731 Stat5b, middle panel), and reblotted with monoclonal pan-Stat5 (lower panel). WB indicates Western blot; PY, .