Prolonged activation of ERK1/2 and expression of JUNB are dependent on sustained gastrin treatment. Sustained and transiently gastrin treated cells were grown and harvested as described in Material and Methods. A-B: Activation of ERK (A) and AKT (B) were analysed at the indicated time points; starting 15 min after gastrin was removed in the transient protocol. Western Blot images of phospho-ERK1/2, total ERK1/2, phospho-AKT and total AKT in untreated (U), sustained (S) and transiently (T) gastrin treated cells. T0: time point zero. Results show one representative of three independent experiments. C: The duration and magnitude of mRNA expression of the AP-1 component Junb were measured by qRT-PCR analysis in cells treated by gastrin in a sustained or transient mode relative to untreated controls at time point zero in one representative experiment (mean fold induction +/− SD of three technical replicates). D: Western Blot image of JUNB protein in whole cell lysate at T0 and 4, 6 and 8 h of untreated (U), sustained (S) and transiently (T) treated cells. Result show one representative of three independent experiments.