TY  - JOUR
AB  - 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. Results: To elucidate the presence and function of VHA-a in the plant complex, three approaches were undertaken: ( i) co-immunoprecipitation with antibodies directed to epitopes in the N- and C-terminal part of VHA-a, respectively, ( ii) immunocytochemistry approach including co-localisation studies with known plant endomembrane markers, and (iii) in vivo-FRET between subunits fused to variants of green fluorescence protein (CFP, YFP) in transfected cells. Conclusions: All three sets of results show that V-ATPase contains VHA-a protein that interacts in a specific manner with other subunits. The genomes of plants encode three genes of the 95 kDa subunit ( VHA-a) of the vacuolar type H+-ATPase. Immuno-localisation of VHA-a shows that the recognized subunit is exclusively located on the endoplasmic reticulum. This result is in agreement with the hypothesis that the different isoforms of VHA-a may localize on distinct endomembrane compartments, as it was shown for its yeast counterpart Vph1.
DA  - 2004
DO  - 10.1186/1471-2121-5-29
LA  - eng
IS  - 1
M2  - 29
PY  - 2004
SN  - 1471-2121
SP  - 29-
T2  - BMC Cell Biology
TI  - Subcellular distribution of the V-ATPase complex in plant cells, and in vivo localisation of the 100 kDa subunit VHA-a within the complex
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-16067826
Y2  - 2024-11-21T22:58:17
ER  -