Figure 1.

END-1 is a sequence-specific DNA-binding protein and transcriptional activator. (A) Electrophoretic mobility shift assay with a radiolabeled GATA probe and nuclear extracts from COS cells transfected with XGATA-4 or END-1 cDNA. Cold competitor oligonucleotides (100× excess) either had the same sequence as the probe (GATA) or replacement of this sequence by GATC or CTTA. In the last two lanes, reactions included preimmune or End-1-specific rabbit antiserum. (B) Fold activation of the GATA-driven luciferase reporter construct αD3 (black bars) or the mutant reporter construct αD4 (in which the GATA site in the promoter is replaced by CTGA; gray bars) after transfection of plasmids encoding END-1, END-1Δ3′, XGATA-4, or XGATA-5.