Fig. 1.

IL-6-induced Erk1/2 pathway activation is amplified by Gab1 in murine embryonic fibroblasts. a Murine embryonic fibroblast (MEF-WT) and Gab1-deficient murine embryonic fibroblast (MEF-Gab1^−/−) cells were seeded and cultivated for 24 h. On the following day, cells were serum-starved for 4 h and subsequently stimulated with Hy-IL-6 (100 ng/ml) for the indicated times. Subsequently, cell lysates were prepared and proteins separated by SDS-PAGE. After Western blotting, membranes were stained for (p)STAT3, STAT3, (p)Y627-Gab1, Gab1, (p)Erk1/2 and Erk1/2. Representative results of n = 3 independent experiments are shown. b For quantification of Gab1 Y627 phosphorylation signals of (p)Y627-Gab1 and Gab1 were analysed via densitometry. The diagram shows the ratio of (p)Y627-Gab1 to Gab1 for each time point. Maximal phosphorylation of Gab1 Y627 in each experiment was set to 100%. Data are given as mean of three independent experiments ± SD. c For quantification of Erk2 phosphorylation, signals of (p)Erk2 and Erk2 were analysed via densitometry. The diagram shows the ratio of (p)Erk2 to Erk2 for each time point. Maximal phosphorylation of Erk2 in each experiment was set to 100%. Data are given as mean of three independent experiments ± SD