Vacuolar-type proton pump ATPases: acidification and pathological relationships.

Vacuolar H(+)(-)translocating ATPase (V-ATPase) is a universal proton pump, and its activity is required for a variety of cell biological processes, such as membrane trafficking, receptor-mediated endocytosis, lysosomal degradation of macromolecules, osteoclastic bone resorption, and the maintenance of acid-base homeostasis by renal intercalated cells. V-ATPase is targeted to various membranes and has different compositions depending on its cellular location. Here, we focus on recent knowledge concerning the targeting mechanism of V-ATPase, a process associated with a wide spectrum of diseases. We also discuss the functions of this enzyme in macrophages and cancer cells-2 characteristic cell types with clinical importance.