ATP4B
Description
The ATP4B (ATPase H+/K+ transporting subunit beta) is a protein-coding gene located on chromosome 13.
The beta subunit of the gastric H(+)/K(+) ATPase pump, which transports H(+) ions in exchange for K(+) ions across the apical membrane of parietal cells. It plays a structural and regulatory role in the assembly and membrane targeting of a functionally active pump. During a transport cycle, the transfer of a H(+) ion across the membrane is coupled to ATP hydrolysis and is associated with a transient phosphorylation of the alpha subunit, shifting the pump conformation from inward-facing (E1) to outward-facing state (E2). It interacts with the phosphorylation domain of the alpha subunit, acting as a ratchet to stabilize the lumenal-open E2 conformation and prevent the reverse reaction of the transport cycle.
ATP4B is also known as ATP6B.
Associated Diseases
- gastric cancer
- gastric adenocarcinoma and proximal polyposis of the stomach
- inflammatory bowel disease 30
