title: GSH-mediated S-transarylation of a quinone glyceraldehyde-3-phosphate dehydrogenase conjugate.
abstract: Many cellular proteins with reactive thiols form covalent bonds with electrophiles, thereby modifying their structures and activities. Here, we describe the recovery of a glycolytic protein, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), from such an electrophilic attack by 1,2-napthoquinone (1,2-NQ). GAPDH readily formed a covalent bond with 1,2-NQ through Cys152 at a low concentration (0.2 μM) in a cell-free system, but when human epithelial A549 cells were exposed to this quinone at 20 μM, only minimal binding was observed although extensive binding to numerous other cellular proteins occurred. Depletion of cellular glutathione (GSH) with buthionine sulfoximine (BSO) resulted in some covalent modification of cellular GAPDH by 1,2-NQ and a significant reduction of GAPDH activity in the cells. Incubation of native, but not boiled, human GAPDH that had been modified by 1,2-NQ with GSH resulted in a concentration-dependent removal of 1,2-NQ from the GAPDH conjugate, accompanied by partial recovery of lost catalytic activity and formation of a 1,2-NQ-GSH adduct (1,2-NQ-SG). While GAPDH is recognized as a multifunctional protein, our results show that GAPDH also has a unique ability to recover from electrophilic modification by 1,2-NQ through a GSH-dependent S-transarylation reaction.
authors.affiliation: Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Miura
authors.forename: Hidenao
authors.initials: H
authors.lastname: Kakehashi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Shinkai
authors.forename: Yuko
authors.initials: Y
authors.lastname: Egara
authors.forename: Reiko
authors.initials: R
authors.lastname: Hirose
authors.forename: Arthur K
authors.initials: AK
authors.lastname: Cho
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Kumagai
mesh_terms: D019328:Buthionine Sulfoximine / Q000009:adverse effects / Q000494:pharmacology; D002460:Cell Line; D002474:Cell-Free System; D003001:Cloning, Molecular; D004847:Epithelial Cells / Q000187:drug effects / Q000201:enzymology*; D004926:Escherichia coli; D005978:Glutathione / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006019:Glycolysis / Q000187:drug effects / Q000235:genetics; D006801:Humans; D009154:Mutation; D009285:Naphthoquinones / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010957:Plasmids; D011489:Protein Denaturation; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism*; D014169:Transformation, Bacterial
chemical_list: D009285:Naphthoquinones; D011994:Recombinant Proteins; D013438:Sulfhydryl Compounds; D019328:Buthionine Sulfoximine; C040756:1,2-naphthoquinone; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D005978:Glutathione