Vacuolar H(+)-ATPase-an enzyme for all seasons.

The life of every eukaryotic cell depends on the function of vacuolar H(+)-ATPase (V-ATPase). Because of its complexity and its challenging properties, the study of this enzyme has lagged behind that of its close relative, F-ATPase. We now know that V-ATPase is vital for many more physiological and biochemical processes than anticipated when the enzyme was discovered a few decades ago. It plays a crucial role in the proper functioning of internal organelles such as vacuoles, lysosomes, synaptic vesicles, endosomes, secretory granules, and the Golgi apparatus as well as in plasma membrane of several organisms and specific tissues and specialized cells. Knowledge of its involvement in several diseases, including cancer, has helped to establish the importance of V-ATPase for the preservation of life.