FIG. 5.

ETO-2 confers repressor function to the SCL complex in transactivation assays. (A) NIH 3T3 cells were transiently transfected with luciferase reporter constructs (pGL3, promoterless; hHS-3.5-IE-hHS+14, under control of the enhancer/promoter regions of the human GATA-1 locus [see schematic representation at the top]) and vectors expressing the indicated transcription factors. The triangle represents increasing amounts of ETO-2 expression vector (75, 150, and 300 ng). Transfection of pGL3 alone provides the baseline reporter activity. (B) Western blot analysis of expression of members of the pentameric complex in the absence (+P) or presence (+P+E) of the ETO-2 expression plasmid. p300 serves as a loading control.