Selenodiglutathione uptake by the Saccharomyces cerevisiae vacuolar ATP-binding cassette transporter Ycf1p.
FEBS J
; 278(21): 4112-21, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-21880115
ABSTRACT
The Saccharomyces cerevisiae vacuolar ATP-binding cassette transporter Ycf1p is involved in heavy metal detoxification by mediating the ATP-dependent transport of glutathione-metal conjugates to the vacuole. In the case of selenite toxicity, deletion of YCF1 was shown to confer increased resistance, rather than sensitivity, to selenite exposure [Pinson B, Sagot I & Daignan-Fornier B (2000) Mol Microbiol36, 679-687]. Here, we show that when Ycf1p is expressed from a multicopy plasmid, the toxicity of selenite is exacerbated. Using secretory vesicles isolated from a sec6-4 mutant transformed either with the plasmid harbouring YCF1 or the control plasmid, we establish that the glutathione-conjugate selenodigluthatione is a high-affinity substrate of this ATP-binding cassette transporter and that oxidized glutathione is also efficiently transported. Finally, we show that the presence of Ycf1p impairs the glutathione/oxidized glutathione ratio of cells subjected to a selenite stress. Possible mechanisms by which Ycf1p-mediated vacuolar uptake of selenodiglutathione and oxidized glutathione enhances selenite toxicity are discussed.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
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Trifosfato de Adenosina
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Compostos Organosselênicos
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Transportadores de Cassetes de Ligação de ATP
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Proteínas de Saccharomyces cerevisiae
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Glutationa
Idioma:
En
Revista:
FEBS J
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
França