In:
Biochemical Journal, Portland Press Ltd., Vol. 448, No. 2 ( 2012-12-01), p. 243-251
Abstract:
ATP-hydrolysis and proton pumping by the V-ATPase (vacuolar proton-translocating ATPase) are subject to redox regulation in mammals, yeast and plants. Oxidative inhibition of the V-ATPase is ascribed to disulfide-bond formation between conserved cysteine residues at the catalytic site of subunit A. Subunits containing amino acid substitutions of one of three conserved cysteine residues of VHA-A were expressed in a vha-A null mutant background in Arabidopsis. In vitro activity measurements revealed a complete absence of oxidative inhibition in the transgenic line expressing VHA-A C256S, confirming that Cys256 is necessary for redox regulation. In contrast, oxidative inhibition was unaffected in plants expressing VHA-A C279S and VHA-A C535S, indicating that disulfide bridges involving these cysteine residues are not essential for oxidative inhibition. In vivo data suggest that oxidative inhibition might not represent a general regulatory mechanism in plants.
Type of Medium:
Online Resource
ISSN:
0264-6021
,
1470-8728
Language:
English
Publisher:
Portland Press Ltd.
Publication Date:
2012
detail.hit.zdb_id:
1473095-9
SSG:
12
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