title: Hyperoxidized peroxiredoxin 2 interacts with the protein disulfide- isomerase ERp46.
abstract: Prx (peroxiredoxin) 2 protects cells from deleterious oxidative damage. It catalyses the breakdown of hydroperoxides through a highly reactive cysteine residue and has been linked to chaperone activity that promotes cell survival under conditions of oxidative stress. It may also be involved in redox signalling by binding to other proteins. In the present study we have searched for binding partners of Prx2 in H2O2-treated Jurkat and human umbilical vein endothelial cells and discovered that the hyperoxidized form selectively co-precipitated with the protein disulfide-isomerase ERp46. Mutant analyses revealed that loss of the peroxidative cysteine residue of Prx2 also facilitated complex formation with ERp46, even without H2O2 treatment, whereas the resolving cysteine residue of Prx2 was indispensible for the interaction to occur. The complex involved a stable non-covalent interaction that was disassociated by the reduction of intramolecular disulfides in ERp46, or by disruption of the decameric structure of hyperoxidized Prx2. This is the first example of a protein interaction dependent on the hyperoxidized status of a Prx.
authors.affiliation: Centre for Free Radical Research, Department of Pathology, University of Otago, P.O. Box 4345, Christchurch 8140, New Zealand.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Pace
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Peskin
authors.forename: Min-Hi
authors.initials: MH
authors.lastname: Han
authors.forename: Mark B
authors.initials: MB
authors.lastname: Hampton
authors.forename: Christine C
authors.initials: CC
authors.lastname: Winterbourn
mesh_terms: D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015151:Immunoblotting; D047468:Immunoprecipitation; D019169:Jurkat Cells / Q000187:drug effects / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D054464:Peroxiredoxins / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D019704:Protein Disulfide-Isomerases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D019704:Protein Disulfide-Isomerases; C480743:TXNDC5 protein, human