PNU156804 disrupts IL-2–mediated p44/42 ERK1/2 phosphorylation.

Quiescent PHA-activated T cells were treated with DMSO (control; lanes a-b) or increasing concentrations of PNU156804 for 16 hours and were stimulated in the presence of 100 nM IL-2 at 37°C for 10 minutes. Cells were lysed, and total cell lysate was separated on 10% SDS-PAGE, transferred to PVDF membrane, Western blotted with antiphospho–p44/42 Erk1/2 (upper panel), stripped, and reprobed with pan-Erk antibody (lower panel). Arrows indicate the location of p44/42 Erk1/2.