FIG. 3.

nAChRɛ promoter-driven luciferase reporter gene activation. C2C12 cells were cotransfected with the indicated alleles of GABPα and -β and a luciferase gene controlled by a 2,200-bp fragment of the mouse nAChRɛ promoter, which harbors the N-box response element. HRG was added when myoblasts were in the middle of differentiating into myotubes. PD was added 30 min prior to HRG. Measurements of luciferase activity were performed 48 h after addition of HRG. The results are presented as the average ratio of luciferase activities from HRG-treated and nontreated cells (corrected for transfection efficiency) for ≥3 independent experiments done in triplicate. The error bars correspond to the standard errors of the means.