Identification of GATA-1 and NF-E2 binding sites in the flanking regions of the human alpha-globin genes.

Some of the elements involved in the erythroid-specific transcriptional regulation of the human gamma- and beta-globin genes and located inside or in the immediate proximity of these genes have been identified as sequences which bind erythroid-specific factors. In the present study, we found two regions located within 1 kb in 5' to the alpha 2- and in 3' to the alpha 1-globin genes which contribute to the induction of human alpha-globin genes following erythroid differentiation in stable MEL transformants. By DNAse I footprinting and gel mobility shift assays, we identified several GATA-1 and one AP-1/NF-E2-binding sites located inside these regions. These results strengthen the idea that, like for all other globin genes, flanking regions contribute in vivo to the regulation of human alpha-globin gene expression.