GATA6 transactivates Id2 and Ncx1. (A) VISTA
comparison of the murine and human Id2 proximal promoter and
exon 1, and (B) of the murine and human Ncx1 proximal promoter
and exon 1. In panels A and B the x and y axes
indicate sequence length (kb) and percent homology (≥ 75%, pink),
respectively. GATA6 binding sites conserved in the mouse and human sequence are
indicated by asterisks. (C) Schematic of the Id2-LUC reporter
containing the 5.2-kb proximal promoter upstream of firefly luciferase (LUC),
and (D) the Ncx1-LUC reporter containing the 5.1-kb proximal
promoter that is also upstream of firefly luciferase. (E) Activation of the
Id2-LUC reporter by GATA6. HL-1 cells were transiently
transfected with Id2-LUC and 125–500 ng of expression
plasmid encoding wild-type GATA6 or GATA6 lacking exon 4 (Gata6Δexon4).
The reporter is activated by wild-type GATA6 but not by GATA6Δexon4. (F).
Activation of the Ncx1-LUC reporter by GATA6. HL-1 cells were
similarly transiently transfected with Ncx1-LUC and
125–500 ng of expression plasmid encoding wild-type GATA6 or
GATA6Δexon4. As with Id2-LUC, the
Ncx1-LUC reporter was activated by the expression of
wild-type GATA6 but not by GATA6Δexon4. The transient transection studies
in panels E and F show the mean change in report activity from at least 3
different experiments at each concentration of expression plasmid.