ATPase, H+/K+ Exchanging Beta Polypeptide (ATP4b)

ATP4b belongs to a family of P-type cation-transporting ATPases. The gastric H+, K+-ATPase is a heterodimer consisting of a high molecular weight catalytic alpha subunit and a smaller but heavily glycosylated beta subunit. This enzyme is a proton pump that catalyzes the hydrolysis of ATP coupled with the exchange of H(+) and K(+) ions across the plasma membrane. Hydrogen-potassium adenosine triphosphatase belongs to a family of P-type cation-transporting ATPases that also includes Ca(2+)-ATPase and Na(+),K(+)-ATPase. In gastric parietal cells, H(+),K(+)-ATPase plays an essential role in the formation of hydrochloric acid. Like the Na(+),K(+)-ATPase, H(+),K(+)-ATPase is a heterodimer consisting of a high molecular weight catalytic alpha subunit and a smaller but heavily glycosylated beta subunit.