Physiology and biochemistry of the kidney vacuolar H+-ATPase.

Vacuolar H+-ATPases have an essential role in renal hydrogen ion secretion in the proximal tubule, collecting duct, and other segments of the nephron. Control of H+ transport is achieved by variations in the intrinsic properties of the renal H+-ATPases and by several cellular regulatory mechanisms, including redistribution of the enzyme both by vesicular traffic and regulated assembly and disassembly, and cytosolic regulatory proteins that interact directly with H+-ATPase. These mechanisms may provide a means for fine control of net acid excretion and for regulating vacuolar H+-ATPases residing on the plasma membrane independently from those in intracellular compartments.