title: Protein glutathionylation: coupling and uncoupling of glutathione to protein thiol groups in lymphocytes under oxidative stress and HIV infection.
abstract: We show here that exposure to oxidative stress induces glutathione (GSH) modification of protein cysteinyl residues (glutathionylation) in T cell blasts. Treating the cells with the oxidant diamide induces thiolation of a series of proteins that can be detected by 2D electrophoresis when 35S-cysteine is used to label the intracellular GSH pool. This thiolation is reversible, proteins are rapidly dethiolated and GSH is released from proteins once the oxidants are washed and the cells are allowed to recover. Dethiolation is dependent on the availability of GSH and thiols, since it is inhibited by GSH-depleting agents and improved by N-acetyl-L-cysteine (NAC). The capacity of these agents to reverse glutathionylation is diminished in T cell blasts infected in vitro with HIV, which is known to cause oxidative stress. Consistent with these findings, the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), an enzyme known to be inhibited by glutathionylation, is inhibited in diamide-treated cells and recovers rapidly when cells are allowed to dethiolate. Further, GAPDH activity is diminished by GSH-depleting agents and augmented by NAC. Thus, reversible glutathionylation of proteins can rapidly shift the activity of a key metabolic enzyme and thereby result in dramatic, reversible changes in cellular metabolism.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA. ghezzi@marionegri.it
authors.forename: Pietro
authors.initials: P
authors.lastname: Ghezzi
authors.forename: Brie
authors.initials: B
authors.lastname: Romines
authors.forename: Maddalena
authors.initials: M
authors.lastname: Fratelli
authors.forename: Ivano
authors.initials: I
authors.lastname: Eberini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Gianazza
authors.forename: Simona
authors.initials: S
authors.lastname: Casagrande
authors.forename: Teresa
authors.initials: T
authors.lastname: Laragione
authors.forename: Manuela
authors.initials: M
authors.lastname: Mengozzi
authors.forename: Leonore A
authors.initials: LA
authors.lastname: Herzenberg
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Herzenberg
mesh_terms: D000111:Acetylcysteine; D003958:Diamide / Q000737:chemistry / Q000378:metabolism; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism*; D015658:HIV Infections / Q000097:blood*; D006801:Humans; D018384:Oxidative Stress; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D013438:Sulfhydryl Compounds; D013601:T-Lymphocytes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011506:Proteins; D013438:Sulfhydryl Compounds; D003958:Diamide; D005978:Glutathione; D000111:Acetylcysteine