Fig. 6.

Nucleotide-mediated ERK1/2 phosphorylation is dependent on EGFR transactivation. BACCs were pretreated with or without AG1478 (2.6 μM) (a), GM6001 (2.5 μM) (b) and dimethylsulfoxide (DMSO) for 15 min, followed by a 10-min stimulation with or without ATP (100 μM) or UTP (100 μM). Blots are representative of three independent experiments performed in triplicate (n = 3); the upper band (phosphorylated or nonphosphorylated) is ERK1 = 44 kDa ,and the lower band is ERK2 = 42 kDa. Blot intensities were measured with the Odyssey Imaging System; values are phosphorylated ERK2 intensity divided by total ERK2 intensity. Bars on the graphs represent mean ± standard error of the mean. *** p < 0.001 vs. stimulator alone