Fig. 2

Tyrosyl phosphorylation of PAK1 promotes S298-MEK1 phosphorylation and ERK activation in response to PRL. a WCL of T47D cells stably overexpressing GFP, PAK1 WT, or PAK1 Y3F treated with PRL (200 ng/ml) for the indicated times were probed for MEK phosphorylation using αpS298-MEK and ERK1/2 activation using αphospho-ERK1/2 (pT202/Y204) antibodies. b, c Graphs represent the densitometric analysis of the bands obtained for phospho-MEK (b) or phospho-ERK1/2 (c) normalized to total MEK or ERK1/2, respectively, for at least 3 independent experiments. Bars represent mean ± SE . *P < 0.05 compared with cells expressing GFP with the same treatment. d WCL of TMX2-28 cells stably overexpressing GFP, PAK1 WT, or PAK1 Y3F treated with PRL (200 ng/ml) for the indicated times were probed with the indicated antibodies. The expression levels of γtubulin were used as an internal loading control