title: Reactive Sulfur Species-Mediated Activation of the Keap1-Nrf2 Pathway by 1,2-Naphthoquinone through Sulfenic Acids Formation under Oxidative Stress.
abstract: Sulfhydration by a hydrogen sulfide anion and electrophile thiolation by reactive sulfur species (RSS) such as persulfides/polysulfides (e.g., R-S-SH/R-S-Sn-H(R)) are unique reactions in electrophilic signaling. Using 1,2-dihydroxynaphthalene-4-thioacetate (1,2-NQH2-SAc) as a precursor to 1,2-dihydroxynaphthalene-4-thiol (1,2-NQH2-SH) and a generator of reactive oxygen species (ROS), we demonstrate that protein thiols can be modified by a reactive sulfenic acid to form disulfide adducts that undergo rapid cleavage in the presence of glutathione (GSH). As expected, 1,2-NQH2-SAc is rapidly hydrolyzed and partially oxidized to yield 1,2-NQ-SH, resulting in a redox cycling reaction that produces ROS through a chemical disproportionation reaction. The sulfenic acid forms of 1,2-NQ-SH and 1,2-NQH2-SH were detected by derivatization experiments with dimedone. 1,2-NQH2-SOH modified Keap1 at Cys171 to produce a Keap1-S-S-1,2-NQH2 adduct. Subsequent exposure of A431 cells to 1,2-NQ or 1,2-NQH2-SAc caused an extensive chemical modification of cellular proteins in both cases. Protein adduction by 1,2-NQ through a thio ether (C-S-C) bond slowly declined through a GSH-dependent S-transarylation reaction, whereas that originating from 1,2-NQH2-SAc through a disulfide (C-S-S-C) bond was rapidly restored to the free protein thiol in the cells. Under these conditions, 1,2-NQH2-SAc activated Nrf2 and upregulated its target genes, which were enhanced by pretreatment with buthionine sulfoximine (BSO), to deplete cellular GSH. Pretreatment of catalase conjugated with poly(ethylene glycol) suppressed Nrf2 activation by 1,2-NQH2-SAc. These results suggest that RSS-mediated reversible electrophilic signaling takes place through sulfenic acids formation under oxidative stress.
authors: †Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.|¶Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors: Yasuhiro
authors: Y
authors: Shinkai
authors: †Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.|¶Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors: Yumi
authors: Y
authors: Abiko
authors: ‡Laboratory of Environmental Health Sciences, Tohoku University School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan.
authors: Tomoaki
authors: T
authors: Ida
authors: †Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors: Takashi
authors: T
authors: Miura
authors: †Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors: Hidenao
authors: H
authors: Kakehashi
authors: §Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan.
authors: Isao
authors: I
authors: Ishii
authors: ∥Division of Cardiocirculatory Signaling, Okazaki Institute for Integrative Bioscience, 5-1 Higashiyama, Myodaiji-cho, Okazaki, Aichi 444-8787, Japan.
authors: Motohiro
authors: M
authors: Nishida
authors: ⊥Department of Microbiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
authors: Tomohiro
authors: T
authors: Sawa
authors: ‡Laboratory of Environmental Health Sciences, Tohoku University School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan.
authors: Takaaki
authors: T
authors: Akaike
authors: †Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.|¶Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors: Yoshito
authors: Y
authors: Kumagai
mesh_terms: D045744:Cell Line, Tumor; D003545:Cysteine / Q000032:analysis / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2 / Q000737:chemistry / Q000378:metabolism*; D009284:Naphthols / Q000737:chemistry / Q000378:metabolism; D009285:Naphthoquinones / Q000737:chemistry / Q000378:metabolism*; D018384:Oxidative Stress; D015398:Signal Transduction; D013434:Sulfenic Acids / Q000737:chemistry / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D009284:Naphthols; D009285:Naphthoquinones; D013434:Sulfenic Acids; D013438:Sulfhydryl Compounds; C050642:1,2-dihydroxynaphthalene; D013455:Sulfur; C040756:1,2-naphthoquinone; D003545:Cysteine