LAT tyrosine phosphorylation by ZAP70/Syk kinases is required for coupling CD2 to ERK1/2 activation.

Wild-type Jurkat, the ZAP70/Syk-deficient cells P116, and the ZAP70-reconstituted P116 cells (P116-ZAP70) were left unstimulated or stimulated for 5 minutes at 37°C with T11₂ + T11₃ or OKT3 and lysed. PNL (0.3 × 10⁶ cell equivalents) were separated by SDS-PAGE and immunoblotted with antiphospho-ERK1/2 antibody as in Figure 10A (upper panel). The same membrane was stripped, cut, and blotted with an anti-ERK1/2 specific antibody (middle panel) and an anti-ZAP70 antibody (lower panel).