Figure 5.

The synergism of G_i and EGF signaling on JNK activity was inhibited by functional disruption of small GTPases. Cos-7 cells were co-transfected with the cDNAs of JNK-HA, ORL₁R, and dominant-negative mutants of small GTPases (RasS17N, RacT17N, RhoT19N or Cdc42T17N) as indicated. The JNK activity was determined at 30 min after individual or simultaneous stimulation with OFQ (100 nM) and EGF (100 ng ml⁻¹). Data shown represent the mean±s.e. from at least three separate experiments, and dotted lines indicate the corresponding basal activities. ^*Individual or simultaneous treatment with OFQ and EGF significantly increased the JNK activity as compared to the basal (Bonferroni's corrected t-test, one-way ANOVA, P<0.05). ^#Simultaneous treatment with OFQ and EGF induced JNK activations synergistically as compared to their individual responses (Bonferroni's corrected t-test, two-way ANOVA, P<0.05).