Subcellular distribution of the V-ATPase complex in plant cells, and in vivo localisation of the 100 kDa subunit VHA-a within the complex

Abstract

Background: Vacuolar H + -ATPases are large protein complexes of more than 700 kDa that acidify endomembrane compartments and are part of the secretory system of eukaryotic cells. They are built from 14 different (VHA)-subunits. The paper addresses the question of sub-cellular localisation and subunit composition of plant V-ATPase in vivo and in vitro mainly by using colocalization and fluorescence resonance energy transfer techniques (FRET). Focus is placed on the examination and function of the 95 kDa membrane spanning subunit VHA-a. Showing similarities to the already described Vph1 and Stv1 vacuolar ATPase subunits from yeast, VHA-a revealed a bipartite structure with (i) a less conserved cytoplasmically orientated N-terminus and (ii) a membrane-spanning C-terminus with a higher extent of conservation including all amino acids shown to be essential for proton translocation in the yeast. On the basis of sequence data VHA-a appears to be an essential structural and functional element of V-ATPase, although previously a sole function in assembly has been proposed.

Arabidopsis tonoplast intrinsic protein and vacuolar H+-adenosinetriphosphatase reflect vacuole dynamics during development of syncytia induced by the beet cyst nematode Heterodera schachtii

“…Tonoplast (a single membrane separating cell sap from the cytosol) contains specific marker proteins such as V-ATPase and TIPs, which regulate and facilitate its functions. V-ATPase is a general marker for tonoplast membrane (Kluge et al 2004). TIPs are also molecular markers of the tonoplast, but different TIPs are markers of different vacuolar compartments.…”

Quantification of Förster resonance energy transfer by monitoring sensitized emission in living plant cells

“…Spectral imaging was reported to be insensitive to autofluorescence and high degree of spectral overlap since the contribution of individual fluorophores can be separated (Megías et al, 2009). In the past, spectral imaging has been combined with acceptor bleaching resulting in a long-lasting procedure that appears not applicable for analysis with subcellular resolution or mobile cytosolic proteins (Kluge et al, 2004; Raicu et al, 2005). …”

Physiological and Transcriptome Analyses of Early Leaf Senescence for ospls1 Mutant Rice (Oryza sativa L.) during the Grain-Filling Stage

“…This protein complex is mainly located in vacuolar membranes, plasma membranes, and other endomembrane systems. It pumps protons into membrane-surrounded intracellular compartments at the expense of hydrolysis energy of ATP and is required to activate secondary transport processes across tonoplast and vesicle dynamics [ 19 , 20 ]. In plants, V-H + -ATPase has been proved to be indispensable in several cellular processes and physiological responses, including membrane trafficking, male gametophyte development [ 21 ], lateral root development, stomatal density and opening [ 22 ], environmental stress tolerance [ 23 ], leaf senescence, and seed dormancy [ 24 ].…”