Molecular cloning and structural analysis of canine gastric H+,K(+)-ATPase.

Gastric hydrogen-potassium ATPase (H+,K(+)-ATPase) is a heterodimeric protein which participates in the formation of hydrochloric acid. We cloned canine H+,K(+)-ATPase alpha and beta subunit cDNAs from canine gastric cDNA libraries and the alpha subunit gene from a canine genomic library. The alpha subunit gene is 13 kb in length and contains 21 introns ranging from 77 to 1,076 bp. Its 5'-flanking region contains putative regulatory motifs for transcription that are similar to those found in H+,K(+)-ATPase genes from other species. The open reading frames of alpha and beta subunit cDNAs are 3,500 and 870 bp in length and encode proteins of 1,034 and 290 amino acids, respectively. They are 80-90% homologous to corresponding cDNAs previously identified in porcine and rodent gastric tissues.