Figure 6.

Erk1/2 phosphorylation in response to flagellin is nucleotide receptor– and calcium-dependent. Cell lysates prepared from NCIH292 cells exposed to flagellin (Flgn, 10 μg/ml, 10 min) were analyzed by Western blot using antibodies directed against phospho-Erk1/2. Membranes were then stripped and reprobed using an antibody against total Erk1/2. The P2Y nucleotide receptor inhibitor Reactive Blue 2 (RB2, 100 μM) and the Ca²⁺ chelator (BAPTA AM, 15 μM) were administered 30 min before and during the 10-min flagellin exposure. Control cells exposed to inhibitor alone were negative for Erk1/2 phosphorylation (not shown).