DNaseI hypersensitive (DH) site mapping around the hEPCR locus. (A) Schematic representation of the hEPCR locus. DH site mapping was performed using BamHI sites at –4.7 and +18.2 kb and EcoRI sites at –3.7 and –20.3 kb, as shown. Black rectangles represent hEPCR exons 1 to 4. Region used as probe is shown as a black box. Arrows indicate DH regions in the hEPCR proximal promoter (PPHS), intron 2 (+2.9HS), and at –5.5 kb (–5.5HS). (B) DH site mapping of EcoRI-digested DNA from different cell types. The EcoRI fragment shown in panel A was detected as a 16.5-kb band. In endothelial cells (HUVECs) and immature hematopoietic cell lines (CEM, KG1, HMC-1), a 1.8-kb band (boxed) was detected, indicative of a DH site at –5.5 kb (–5.5HS). Lane 1 indicates DNA undigested with DNaseI.