Tyrosine phosphorylation induced by PAF in CHO cell lines.

Cells (2.5 × 10⁶/mL) were incubated with 1 mg/mL Fg for 15 minutes at room temperature in a 250 μL final volume and then stimulated with 100 nM PAF and plated onto BSA-precoated wells. After 15 minutes, cells were lysed and proteins (50 μg) were separated by 6% to 16% SDS-PAGE, transferred to PVDF sheets and probed with antiphosphotyrosine mAb PY99, as described in “Materials and methods.” The arrows point to phosphorylated p100-PPA and MAPK proteins.