GATA4 and WT1 transcriptionally cooperate to activate the SRY promoter. A. In addition to multiple GATA motifs, two potential WT1 binding sites (indicated by gray circles) are present in the first 2 kilobases of the mouse, human, and pig SRY promoters. B. Nucleotide sequence of the potential WT1 binding sites in the mouse, pig, and human SRY promoters. C. Western blot analysis of HeLa cells extracts (10 μg) overexpressing GATA4 and/or WT1 (+/- KTS) isoforms. D. WT1 and GATA4 transcriptionally cooperate. HeLa cells were co-transfected with either a -1090 bp mouse, -1400 bp pig, or -1250 bp human SRY-luciferase promoter construct (500 ng) along with an empty vector or expression vectors (500 ng) for WT1(-KTS) or WT1(+KTS) in the absence (-) or presence (+) of GATA4 (50 ng). All promoter activities are reported as fold activation over control ± S.E.M. Like letters indicate no statistically significant difference between groups (P > 0.05).