Structure, function and regulation of the plant vacuolar H+-translocating ATPase

The plant V-ATPase is a primary-active proton pump present at various compo nents of the endomembrane system. It is assembled by different protein subu nits which are located in two major domains, the membrane-integral V-o-doma in and the membrane peripheral V-1-domain. At the plant vacuole the V-ATPas e is responsible for energization of transport of ions and metabolites, and thus the V-ATPase is important as a 'house-keeping' and as a stress respon se enzyme. It has been shown that transcript and protein amount of the V-AT Pase are regulated depending on metabolic conditions indicating that the ex pression of V-ATPase subunit is highly regulated. Moreover, there is increa sing evidence that modulation of the holoenzyme structure might influence V -ATpase activity, (C) 2000 Elsevier Science B.V. All rights reserved.