The anion exchange protein AE1 is the most abundant membrane protein in human erythrocytes mediating the electroneutral chloride/bicarbonate exchange. We identified a promoter region in the 5' flanking region of the human AE1 gene which controls transcription in a cell type independent manner. In addition a second, distal promoter element mediates gene expression only in erythroid cells and in dependence upon differentiation. Within this distal promoter region we defined a 44 bp sequence containing a novel CT-rich motif with very strong promoter activity whereas a second 28 bp segment suppresses gene expression.