Table 1.
Differences Between the Regulation of the Mouse and Human HO-1 Genes
| Feature | Mouse HO-1 gene | Human HO-1 gene |
|---|---|---|
| Promoter elements | E1 and E2 regionsa (all stimuli) | A and B regionsb (limited stimuli) |
| GT repeat region in promoter | Absent | Present |
| Additional regulatory elements | None detected | Internal enhancer |
| Heme response element | E1 and E2 regions | Internal enhancer + A and B regions |
| Cadmium response element | (T/C)GCTGAGTCA (E1 region) | TGCTAGATTT (region A) |
| Response to hyperoxia | E1 region | A and B regions are nonfunctional |
| Responsive to hypoxia | Gene activation | Gene repression |
| Responsive to interferon γ | Gene activation | Gene repression |
| Responsive to heat shock | Gene activation | Nonresponsive |
| Response to oxidized lipids | E1 region | Region between −9.1 and −11.6 kb |
| Response to hyperosmolarity | Gene activation | Gene repression |
Reproduced with permission from Sikorski et al. (125).
a
E1 and E2 = −4.0 and −10 kb distal promoter elements upstream of the HO-1 gene in mice.
b
A and B regions = analogous to E1 and E2 in mice. −4.0 and −9 kb distal promoter elements for human HO-1 gene containing stress and cadmium response elements.
HO, heme oxygenase.