Vacuolar H+ pumping ATPases in luminal acidic organelles and extracellular compartments: common rotational mechanism and diverse physiological roles.

Cytoplasmic organelles with an acidic luminal pH include vacuoles, coated vesicles, lysosomes, the Golgi apparatus, and synaptic vesicles. Acidic compartments are also known outside specialized cells such as osteoclasts. The unique acidic pH is formed by V-ATPase (Vacuolar type ATPase), other ion transporters, and the buffering action of proteins inside the organelles. V-ATPase hydrolyzes ATP and transports protons inside an organelle or extracellular compartment. We have summarized recent progress on mouse V-ATPases and their varying localizations together with their mechanism emphasizing similarities with F-type ATPases.