title: Renal vacuolar H+-ATPase.
abstract: Vacuolar H(+)-ATPases are ubiquitous multisubunit complexes mediating the ATP-dependent transport of protons. In addition to their role in acidifying the lumen of various intracellular organelles, vacuolar H(+)-ATPases fulfill special tasks in the kidney. Vacuolar H(+)-ATPases are expressed in the plasma membrane in the kidney almost along the entire length of the nephron with apical and/or basolateral localization patterns. In the proximal tubule, a high number of vacuolar H(+)-ATPases are also found in endosomes, which are acidified by the pump. In addition, vacuolar H(+)-ATPases contribute to proximal tubular bicarbonate reabsorption. The importance in final urinary acidification along the collecting system is highlighted by monogenic defects in two subunits (ATP6V0A4, ATP6V1B1) of the vacuolar H(+)-ATPase in patients with distal renal tubular acidosis. The activity of vacuolar H(+)-ATPases is tightly regulated by a variety of factors such as the acid-base or electrolyte status. This regulation is at least in part mediated by various hormones and protein-protein interactions between regulatory proteins and multiple subunits of the pump.
authors.affiliation: Institute of Physiology, Univ. of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland. Wagnerca@access.unizh.ch
authors.forename: Carsten A
authors.initials: CA
authors.lastname: Wagner
authors.forename: Karin E
authors.initials: KE
authors.lastname: Finberg
authors.forename: Sylvie
authors.initials: S
authors.lastname: Breton
authors.forename: Vladimir
authors.initials: V
authors.lastname: Marshansky
authors.forename: Dennis
authors.initials: D
authors.lastname: Brown
authors.forename: John P
authors.initials: JP
authors.lastname: Geibel
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D006801:Humans; D007668:Kidney / Q000201:enzymology* / Q000648:ultrastructure; D025262:Vacuolar Proton-Translocating ATPases / Q000502:physiology*
chemical_list: D025262:Vacuolar Proton-Translocating ATPases