Regulation of the V-type ATPase by redox modulation.
Biochem J
; 448(2): 243-51, 2012 Dec 01.
Article
em En
| MEDLINE
| ID: mdl-22943363
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 Cys(256) 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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arabidopsis
/
ATPases Vacuolares Próton-Translocadoras
/
Proteínas de Arabidopsis
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article