title: Multilevel regulation of 2-Cys peroxiredoxin reaction cycle by S-nitrosylation.
abstract: S-nitrosothiols (SNOs), formed by nitric oxide (NO)-mediated S-nitrosylation, and hydrogen peroxide (H2O2), a prominent reactive oxygen species, are implicated in diverse physiological and pathological processes. Recent research has shown that the cellular action and metabolism of SNOs and H2O2 involve overlapping, thiol-based mechanisms, but how these reactive species may affect each other's fate and function is not well understood. In this study we investigated how NO/SNO may affect the redox cycle of mammalian peroxiredoxin-1 (Prx1), a representative of the 2-Cys Prxs, a group of thioredoxin (Trx)-dependent peroxidases. We found that, both in a cell-free system and in cells, NO/SNO donors such as S-nitrosocysteine and S-nitrosoglutathione readily induced the S-nitrosylation of Prx1, causing structural and functional alterations. In particular, nitrosylation promoted disulfide formation involving the pair of catalytic cysteines (Cys-52 and Cys-173) and disrupted the oligomeric structure of Prx1, leading to loss of peroxidase activity. A highly potent inhibition of the peroxidase catalytic reaction by NO/SNO was seen in assays employing the coupled Prx-Trx system. In this setting, S-nitrosocysteine (10 μM) effectively blocked the Trx-mediated regeneration of oxidized Prx1. This effect appeared to be due to both competition between S-nitrosocysteine and Prx1 for the Trx system and direct modulation by S-nitrosocysteine of Trx reductase activity. Our findings that NO/SNO target both Prx and Trx reductase may have implications for understanding the impact of nitrosylation on cellular redox homeostasis.
authors.affiliation: Department of Biochemistry, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Rotem
authors.initials: R
authors.lastname: Engelman
authors.forename: Pnina
authors.initials: P
authors.lastname: Weisman-Shomer
authors.forename: Tamar
authors.initials: T
authors.lastname: Ziv
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Xu
authors.forename: Elias S J
authors.initials: ES
authors.lastname: Arnér
authors.forename: Moran
authors.initials: M
authors.lastname: Benhar
mesh_terms: D000818:Animals; D002384:Catalysis; D003545:Cysteine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009569:Nitric Oxide / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D013880:Thioredoxin-Disulfide Reductase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D004220:Disulfides; D018398:Homeodomain Proteins; C082157:PRRX1 protein, human; C489936:Prrx1 protein, mouse; D009569:Nitric Oxide; D013880:Thioredoxin-Disulfide Reductase; D003545:Cysteine