Figure 1. Identification of NKX2-5 binding sites in β-catenin (CTNNB1) and GATA4 promoters.

The promoter sequence of β-catenin and GATA4 genes contains candidate NKX2.5 binding sites (boxed sequences). The first exons of β-catenin and GATA4 are indicated with capital-bold letters and primers: BF1, BR1, GF1, and GR1 used in ChIP analysis are underlined. Primers GF2, GR2, BF2, and BR2 (underlined) delineate the region cloned and used in luciferase assay. The base changes in the NKE sequences (mNKEs), used in gene reporter assays have been shown. The bottom panel shows the level of DNA sequence conservation between human and mouse 2-kb upstream of β-catenin and GATA4 first exons. Shaded areas demonstrate very high level of conservation. Black boxes indicate the identified NKEs.