Alternative titles; symbols
HGNC Approved Gene Symbol: ATP4A
Cytogenetic location: 19q13.12 Genomic coordinates (GRCh38): 19:35,550,031-35,563,658 (from NCBI)
Hydrogen-potassium ATPase is responsible for acid secretion into the stomach and catalyzes electroneutral exchange of cytoplasmic hydrogen ions and external potassium ions coupled with ATP hydrolysis. The enzyme is found in gastric parietal cells where it is located in cytoplasmic vesicles or apical plasma membranes of the secretory canaliculus. Maeda et al. (1990) cloned the human gastric hydrogen-potassium ATPase gene and determined its nucleotide sequence. The gene encodes a protein of 1,035 residues including the initiator methionine.
Maeda et al. (1990) determined that the 15-kb ATP4A gene contains 22 exons. The position of introns is similar to that in human sodium-potassium ATPase alpha-1 (ATP1A1; 182310) and alpha-3 (ATP1A3; 182350) subunits; however, the first introns of the 2 enzymes are difficult to align, and unlike the finding in the sodium-potassium ATPase gene, the sixth exon in the hydrogen-potassium ATPase gene is not separated by an intron.
By fluorescence in situ hybridization, Song et al. (1992) mapped the ATP4A gene (formerly symbolized ATP6A) to 19q13.1 in the same region as the ATP1A3 gene, which shows about 70% cDNA homology.
Maeda, M., Oshiman, K.-I., Tamura, S., Futai, M. Human gastric (H(+) + K(+))-ATPase gene: similarity to (Na(+) + K(+))-ATPase genes in exon/intron organization but difference in control region. J. Biol. Chem. 265: 9027-9032, 1990. [PubMed: 2160952]
Song, I., Yamada, T., Trent, J. M. Mapping of the gene encoding the alpha-subunit of the human H(+),K(+)-ATPase to chromosome 19q13.1 by fluorescent in situ hybridization. Genomics 14: 547-548, 1992. [PubMed: 1330887] [Full Text: https://doi.org/10.1016/s0888-7543(05)80266-6]