FIG. 5.

EWS/FLI-1 blocks MyoD-dependent and myogenin-dependent transcriptional activation of a myogenin-lacZ reporter. 293T cells were transfected with MyoD (A) or myogenin (B) plasmid and a β-galactosidase (lacZ) reporter driven by 5′ regulatory regions from the myogenin gene (6, 7) and either control vector (neo), type I EWS/FLI-1 (EF-1), the point mutant EWS/FLI-1 R2L2, or a plasmid containing only the portion of FLI-1 present in the EWS/FLI-1 fusion [Fli-1(C)]. Transcriptional activation of the reporter was scored by the lacZ-positive colony number. Data were normalized for differences in transfection efficiency by cotransfection of a green fluorescent protein plasmid. The baseline myogenin-lacZ colony number (control plasmid and myogenin-lacZ only) is shown at the far left. Error bars represent the standard errors of duplicate experiments.