FIGURE 6.

MEF2A promoter NRF1 element mutation and nrf1 RNAi reduce promoter activity in myocytes. Indicated MEF2A promoter 1 (A) or promoter 2 (B) reporters were co-transfected with SV40-βgal into C2C12 cells. Data were analyzed as described for Fig. 4D. C, subclonfluent C2C12 cells (upper panel) in a 12-well plate were transfected with 5 nm ds-siRNA directed at no gene (control) or nrf1. After 72 h, cells were co-transfected with S-MEF2ap₂-Luc and SV40-βgal followed by analyses as described for Fig. 4D. Human HEK 293 cells (lower panel) were transfected once with 5 nm ds-siRNA directed at no gene (control) or NRF1. After 2 days, cells were cotransfected with S-MEF2Ap₂-Luc and SV40-βgal and analyzed as described for Fig. 4D except that cell extracts were harvested after 24 h.