THE STRUCTURE AND ORGANIZATION OF THE HUMAN ERYTHROID ANION-EXCHANGER(AE1) GENE

The AE1 (anion exchanger, band 3) protein is expressed in erythrocytes and in the A-type intercalated cells of the kidney distal collecting tubule. In both cell types it mediates the electroneutral transport of chloride and bicarbonate ions across the lipid bilayer, and, in eryth rocytes, it also serves as the critical attachment site of the periphe ral membrane skeleton. We have characterized the human AE1 gene using overlapping clones isolated from a phage library of human genomic DNA. The gene spans similar to 20 kb and consists of 20 exons separated by 19 introns. The structure of the human AE1 gene corresponds closely w ith that of the previously characterized mouse AE1 gene, with a high d egree of conservation of exon/intron junctions, as well as exon and in tron nucleotide sequences. The putative upstream and internal promoter sequences of the human AE1 gene used in erythroid and kidney cells, r espectively, are described. We also report the nucleotide sequence of the entire 3' noncoding region of exon 20, which was lacking in the pu blished cDNA sequences. In addition, we have characterized 9 Alu repea t elements found within the body of the human AE1 gene that are member s of 4 related subfamilies that appear to have entered the genome at d ifferent times during primate evolution. (C) 1994 Academic Press Inc.