FIG. 8.

Anti-CD3 MAb-stimulated Erk activation in P116 cells can be blocked by PP-1. Jurkat cells and P116 cells at 6 × 10⁷ cells/ml were preincubated for 15 min at 37°C with the indicated concentration of PP-1, prior to stimulation at 37°C with either OKT3 ascites (1:50) for 3 min or 50 ng of PMA per ml for 15 min. Erk activation was measured as described in the legend to Fig. 1.