Fig 3. Regulation of ALK kinase activity by intracellular phosphatases.

RH30, RH4 and SH-SY-5Y cells were treated with Pervanadate (A) or agonist mAb46 monoclonal antibody (B). Immunoblottings of total and phosphorylated ALK, c-Met (MET), ERK and AKT proteins are shown. (C) Regulation of inducible ALK phosphorylation and activity. RH30, RH4 and SH-SY-5Y cells were treated with both mAb46 (3 μg/ml) and Pervanadate (50 μM) to measure ALK phosphorylation and signalling. To inhibit ALK, the cells were pre-incubated with antagonist mAb30 antibody (2 μg/ml) or with Crizotinib inhibitor (1 μM). Protein lysates were subjected to Western blot analysis using antibodies specific for total and phosphorylated ALK and ERK proteins, as described.