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Article Dans Une Revue Molecular Biology of the Cell Année : 2011

Gex1 is a yeast glutathione exchanger that interferes with pH and redox homeostasis.

Résumé

In the yeast S. cerevisiae, glutathione plays a major role in heavy metal detoxification and protecting cells against oxidative stress. We show here that Gex1 is a new glutathione exchanger. Gex1 and its paralog Gex2 belong to the major facilitator superfamily (MFS) of transporters and display similarities to the ARN (Aft1-regulon) family of siderophore transporters. Gex1 was found mostly at the vacuolar membrane and, to a lesser extent, at the plasma membrane. Gex1 expression was induced under conditions of iron depletion and was principally dependent on the iron-responsive transcription factor Aft2. However, a gex1Δ gex2Δ strain displayed no defect in known siderophore uptake. The deletion mutant accumulated intracellular glutathione and cells overproducing Gex1 had low intracellular glutathione contents, with glutathione excreted into the extracellular medium. Furthermore, the strain overproducing Gex1 induced acidification of the cytosol, confirming the involvement of Gex1 in proton transport, as a probable glutathione/proton antiporter. Finally, the imbalance of pH and glutathione homeostasis in the gex1Δ gex2Δ and Gex1-overproducing strains led to modulations of the cAMP/PKA and PKC1-MAPK signaling pathways.

Dates et versions

hal-00593564 , version 1 (16-05-2011)

Identifiants

Citer

Manel Dhaoui, Françoise Auchère, Pierre-Louis Blaiseau, Emmanuel Lesuisse, Ahmed Landoulsi, et al.. Gex1 is a yeast glutathione exchanger that interferes with pH and redox homeostasis.. Molecular Biology of the Cell, 2011, epub ahead of print. ⟨10.1091/mbc.E10-11-0906⟩. ⟨hal-00593564⟩
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