Effect of G-Gly on JNK activity. Cells were lysed after a 30-min treatment with Leu15-G(2–17)-Gly (10−8 M). Lysates (lane 1, LoVo control; lane 2, LoVo with Leu15-G(2–17)-Gly; lane 3, HT 29 control; lane 4, HT 29 with Leu15-G(2–17)-Gly) were then immunoprecipitated and an in-gel JNK assay was performed as described in Materials and Methods. The gel shown above is representative of at least three others with similar results. Densitometric measurement revealed an average 2.3 ± 0.5 fold induction in LoVo cells and a 1.3 ± 0.1 fold induction in HT 29 cells. Mean ± SD of three different experiments, p < 0.05 versus control.