Fig. 8.

Requirement of JNK in neuregulin-induced AChR ε-transgene expression. C2C12 myoblasts were transiently transfected with ε416-Luc and pCMVβ with pCMV, pCMV–JNK1(WT), pCMV–JNK1(ALF), pCMV–MKK4(Glu), pCMV–MKK4(Ala), pCMV–p38(WT), or pCMV–p38(AGF). Twenty-four hours after transfection, myoblasts were incubated with the DM to induce myotube formation. After another 48 hr, myotubes were stimulated with 1 nm neuregulin for 24 hr and then harvested for assays of luciferase and β-galactosidase activity. The fold of the relative luciferase or β-galactosidase activity in neuregulin-stimulated cells over that in control cells is shown. Histograms are mean ± SD of four different samples. *p < 0.05.