A promoter activity assay in K562 human erythroleukemia cells revealed that the presence of this 130-base pair region increased the promoter activity of the ALAS2 gene by 10-15-fold.
To test the hypothesis that ALAS2 expression might be regulated by a similar mechanism, we exposed murine erythroleukemia cells to hypoxia (1% O(2)) and found an up to 3-fold up-regulation of ALAS2 mRNA levels and an increase in cellular heme content.