Figure 3.

RFP blocks Epc1-induced potentiation of SRF-dependent differentiation of skeletal myoblasts. (a) Epc1 potentiated SRF-induced multinucleation of H9c2 cells in differentiation medium. However, the potentiation was completely blocked by co-transfection of RFP. Note that multinucleation after RFP transfection returned to that of the SRF-level. (b) Epc1-induced potentiation of SRF-transactivation was completely absent after co-transfection of RFP in 293T cells. (c) The same results of promoter analysis were obtained from C2C12 myoblast cells. (d) Representative western blot analysis showing that Epc1-induced potentiation of SRF-mediated expression of muscle-specific genes was blocked by RFP. (e and g) Quantification results from three independent western blots of skeletal α-actin (e), MyoD (f), and myogenin (g). NS, not significant. (h) Western blot analysis of Epc1- or Epc1/Rfp- knockdown C2C12 cells. The knockdown cells were prepared with antisense technology. Expression of myogenin and desmin was decreased in antisense Epc1 cells and it was recovered in antisense Epc1/Rfp cells. (i) Quantification results from three western blots of myogenin. (j) Quantification results from western blots of desmin. ^*P<0.05, ^**P<0.01