title: Bifunctional electrophiles cross-link thioredoxins with redox relay partners in cells.
abstract: Thioredoxin protects cells against oxidative damage by reducing disulfide bonds in improperly oxidized proteins. Previously, we found that the baker's yeast cytosolic thioredoxin Trx2 undergoes cross-linking to form several protein-protein complexes in cells treated with the bifunctional electrophile divinyl sulfone (DVSF). Here, we report that the peroxiredoxin Tsa1 and the thioredoxin reductase Trr1, both of which function in a redox relay network with thioredoxin, become cross-linked in complexes with Trx2 upon DVSF treatment. Treatment of yeast with other bifunctional electrophiles, including diethyl acetylenedicarboxylate (DAD), mechlorethamine (HN2), and 1,2,3,4-diepoxybutane (DEB), resulted in the formation of similar cross-linked complexes. Cross-linking of Trx2 and Tsa1 to other proteins by DVSF and DAD is dependent on modification of the active site Cys residues within these proteins. In addition, the human cytosolic thioredoxin, cytosolic thioredoxin reductase, and peroxiredoxin 2 form cross-linked complexes to other proteins in the presence of DVSF, although each protein shows different susceptibilities to modification by DAD, HN2, and DEB. Taken together, our results indicate that bifunctional electrophiles potentially disrupt redox homeostasis in yeast and human cells by forming cross-linked complexes between thioredoxins and their redox partners.
authors: Biochemistry and Molecular Biology Program, Departments of Biology and Chemistry, The College of Wooster, Wooster, Ohio 44691, United States.
authors: Matthew R
authors: MR
authors: Naticchia
authors: Haley A
authors: HA
authors: Brown
authors: Francisco J
authors: FJ
authors: Garcia
authors: Andrew M
authors: AM
authors: Lamade
authors: Samantha L
authors: SL
authors: Justice
authors: Rachelle P
authors: RP
authors: Herrin
authors: Kevin A
authors: KA
authors: Morano
authors: James D
authors: JD
authors: West
mesh_terms: D045744:Cell Line, Tumor; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D013450:Sulfones / Q000737:chemistry / Q000378:metabolism*; D013880:Thioredoxin-Disulfide Reductase / Q000737:chemistry / Q000378:metabolism*; D013879:Thioredoxins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D029701:Saccharomyces cerevisiae Proteins; D013450:Sulfones; C516110:TRX2 protein, S cerevisiae; D013879:Thioredoxins; C009873:divinyl sulfone; D010544:Peroxidases; C496253:Tsa1 protein, S cerevisiae; D013880:Thioredoxin-Disulfide Reductase