title: Sulfiredoxin Translocation into Mitochondria Plays a Crucial Role in Reducing Hyperoxidized Peroxiredoxin III.
abstract: The mitochondria are the major intracellular source of reactive oxygen species (ROS), which are generated during cellular respiration. The role of peroxiredoxin (Prx) III, a 2-Cys Prx family member, in the scavenging of mitochondrial H(2)O(2) has recently been emphasized. While eliminating H(2)O(2), Prx can become overoxidized and inactivated by modifying the active cysteine into cysteine sulfinic acid (Cys-SO(2)H). When 2-Cys Prxs are inactivated in vitro, sulfiredoxin (Srx) reduces the cysteine sulfinic acid to cysteines. However, whereas Srx is localized in the cytoplasm, Prx III is present exclusively in the mitochondria. Although Srx reduces sulfinic Prx III in vitro, it remains unclear whether the reduction of Prx III in cells is actually mediated by Srx. Our gain- and loss-of-function experiments show that Srx is responsible for reducing not only sulfinic cytosolic Prxs (I and II) but also sulfinic mitochondrial Prx III. We further demonstrate that Srx translocates from the cytosol to mitochondria in response to oxidative stress. Overexpression of mitochondrion-targeted Srx promotes the regeneration of sulfinic Prx III and results in cellular resistance to apoptosis, with enhanced elimination of mitochondrial H(2)O(2) and decreased rates of mitochondrial membrane potential collapse. These results indicate that Srx plays a crucial role in the reactivation of sulfinic mitochondrial Prx III and that its mitochondrial translocation is critical in maintaining the balance between mitochondrial H(2)O(2) production and elimination.
authors.affiliation: College of Pharmacy, Division of Life & Pharmaceutical Sciences, and Center for Cell Signaling & Drug Discovery Research, Ewha Womans University, Science Building C, 11-1 Daehyun-dong, Seodaemun-gu, Seoul 120-750, Korea.
authors.forename: You Hyun
authors.initials: YH
authors.lastname: Noh
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Baek
authors.forename: Woojin
authors.initials: W
authors.lastname: Jeong
authors.forename: Sue Goo
authors.initials: SG
authors.lastname: Rhee
authors.forename: Tong-Shin
authors.initials: TS
authors.lastname: Chang
mesh_terms: D017209:Apoptosis / Q000502:physiology; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008928:Mitochondria / Q000201:enzymology* / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D050862:Oxidoreductases Acting on Sulfur Group Donors; D010101:Oxygen Consumption / Q000502:physiology*; D061105:Peroxiredoxin III; D054464:Peroxiredoxins / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D013441:Sulfinic Acids / Q000378:metabolism
chemical_list: D024101:Mitochondrial Proteins; D013441:Sulfinic Acids; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C516115:PRDX3 protein, human; D061105:Peroxiredoxin III; D054464:Peroxiredoxins; D050862:Oxidoreductases Acting on Sulfur Group Donors; C504024:SRXN1 protein, human; D003545:Cysteine