Potassium-transporting ATPase subunit alpha

The potassium-transporting ATPase subunit alpha, also known as the H+, K+-ATPase alpha subunit, is the catalytic component of the gastric proton pump. It is primarily responsible for exchanging protons (H+) for potassium ions (K+) across cellular membranes, a process that is essential for acid secretion in the stomach and also plays roles in renal physiology. It uses ATP hydrolysis to transport protons out of cells in exchange for potassium ions into cells. In gastric parietal cells, this activity leads to acidification of the stomach contents by secreting hydrogen ions into the gastric lumen while absorbing potassium ions. Dysfunction or inhibition of this pump can lead to disorders such as hypochlorhydria, metabolic alkalosis/acidosis due to impaired renal function, or be targeted therapeutically with drugs like proton pump inhibitors used to treat peptic ulcers and gastroesophageal reflux disease.

Other names

H+, K+-ATPase alpha subunitPotassium-transporting ATPase alpha chain 1Gastric H+/K+ ATPase α-subunitATP4A

Inhibition of H+, K+-ATPase activity, reducing gastric acid secretion