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 αand β subunit cDNAs from canine gastric cDNA libraries and the αsubunit gene from a canine genomic library. The αsubunit gene is 13 kb in length and contains 21 introns ranging from 77 to 1,076 bp. Its 5ߣ-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 αand β 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.