Fig. 3.
RosA inhibits TCR-induced tyrosine phosphorylation of PLC-γ1.
Jurkat cells (5 × 107) were preincubated with 30 μM (A) or 3 to 15 μM RosA (B) for 4 hours and then either unstimulated or stimulated with OKT3 ascites (1:200) and OKT3–cross-linking antimouse IgG antibody (40 μg/mL) at 37°C for 2 minutes. PLC-γ1 was immunoprecipitated with anti–PLC-γ1 mAb (5 μg/mL), and tyrosine phosphorylation (PTyr) status was determined by blotting with antiphosphotyrosine mAb (0.5 μg/mL). After stripping, the nitrocellulose membrane was reblotted with rabbit polyclonal anti–PLC-γ1 antibody (1 μg/mL) to confirm equal precipitation of PLC-γ1. Results represent 1 of 4 independent experiments.
