MOLECULAR-CLONING AND CHARACTERIZATION OF THE HUMAN AE2 ANION-EXCHANGER (SLC4A2) GENE

The human AE2 gene (HGMW-approved symbol SLC4A2) encompasses over 17 k b and contains 23 exons intervened by 22 introns. The size range for t he exons is 90-255 bp, whereas that for the introns is 80 bp to 2.2 kb . Exon 1 consists solely of 5'-untranslated sequence, and exon 2 encod es the amino-terminal end of the antiport protein. Primer extension ex periments suggest that there are multiple transcription initiation sit es in leukocytes, The putative promoter region of the human AE2 gene c ontains no obvious TATA or CCAAT elements in the expected positions bu t has GC boxes, proposed sites for binding Spl transcription factor. T hese features, as well as the presence of several consensus elements s uch as GATA, LBP-1, E-box, CACC box, and T-antigen motif, indicate tha t the human AE2 promoter resembles the erythroid promoter of the human AE1 gene. The human AE2 gene (which has been previously mapped to chr omosome 7) has three more introns than the human AE1 gene (mapped to c hromosome 17), but downstream of intron 7 in the AE2 gene (correspondi ng to intron 4 in the AE1 gene), these two genes show a rather similar exon/intron organization. (C) 1997 Academic Press