Fig. 3. PMA inhibits phosphorylation of paxillin tyrosine residues 31 and 118. Baf3 cells were stably transfected with EGFP (vector) or EGFP-conjugated wild-type -paxillin or the -paxillin YF tyrosine phosphorylation mutants 31, 118, 31/118, 40/181, 31/40/118/181, 31/40/181/434/488 and 40/118/181/434/488. Cells were grown on 10 ng/ml IL-3 and aliquots were treated with 100 nM PMA for 30 minutes. After immunoprecipitation with anti-paxillin antibody (IP:Pax), lysates were analyzed on western blots with a mixture of anti-phosphotyrosine antibodies 4G10 and PY20 (IB:PY) or with anti-GFP (IB:GFP) antibody.