SLC4A1 is a gene that spans 19.757 kb of genomic DNA on the long arm of chromosome 17, in the telomere-to-centromere orientation. The gene consists of twenty exons of which the first exon is non-coding. The start codon is located at the beginning of exon 2 and the stop codon in the beginning of exon 20.

The SLC4A1 mRNA is 4.953 kb long. In the Ensembl database, its mRNA is 4.965 kb long. Compared with NCBI database, the beginning additional bases are GCTGTCA; the stop bases are GTGGC. However the coding sequences of them are the same. There are also five other transcripts: 419 bp, 1922 bp and 460 bp, that encode no protein, and 393 bp 462 bp, that encode other proteins.

911 amino acids; 95 kDa.

Anion exchanger protein 1 (AE1), is a classical cell membrane transporter, also called band 3, that participates in the regulation of intracellular pH and ion homeostasis in vivo by transmembrane Cl^-/HCO3^- exchange. The C-terminal region of AE1 directly interacts with tumor suppressor p16, and then, it sequestrates p16 protein in the cytoplasm and causes gastric cancer. The transmembrane of AE2 interfered with AE1. They can form heterodimers. AE2 was degradated through ubiquitination by APC in the cytoplasm. Clinical data analysis showed that abnormal expression of AE1 with p16 is correlated with occurrence and development of gastric cancer.

Anion exchanger.

Point mutations in promoter of AE1 gene were detected in AE1 positive gastric and colon cancer cells.

These mutations were only detected in cancer, not in normal cells.