Figure 4.

c-Myc protein expression is induced by GyrB-ALK activation. To determine basal level of kinase activation in the absence of coumermycin, Rat1A fibroblasts were transiently transfected with 0 to 12 μg of the Myc-GyrB-ALK expression construct. Cells were then lysed and equivalent amounts of lysate were analyzed by immunoblotting with 9E10 anti-Myc mAb (α Myc) and RC-20 anti-phosphotyrosine (α pTyr) antibodies. With increasing expression, increasing autophosphorylation of Myc-GyrB-ALK was seen. While performing gene dosage studies, we observed an increase in a protein the approximate size of c-Myc on 9E10 immunoblots (open circle).