ZnPP and ZnCl2 responsive elements in the mouseHO-1 gene transfected to HA-1 cells.
A partial restriction map and structural organization of the mouseHO-1 gene and the 5′-flanking region are shown. Position +1 represents the transcription initiation site. The location of the EH and SX2 enhancer elements are indicated by solid bars. B indicates BamHI; E, EcoRI; H, HindIII; X, XhoI. HA-1 cells were transiently transfected with the indicated CAT constructs and incubated with 10 μM ZnPP or 100 μM ZnCl2 for 24 hours. The CAT assay was carried out as described under “Materials and methods.” The data represent the average value from 3 independent experiments and the mean fold induction of CAT activity in extracts of cells incubated with ZnPP or ZnCl2 compared to that in extracts of cells incubated with the constructs alone.
