title: Human sensitive to apoptosis gene protein inhibits peroxynitrite-induced DNA damage.
abstract: Sensitive to apoptosis gene (SAG) protein, a novel zinc RING finger protein, which is redox responsive and protects mammalian cells from apoptosis, is a metal chelator and a potential reactive oxygen species scavenger, but its antioxidant properties have not been completely defined. The present study was undertaken to test the hypothesis that human SAG protects from DNA damage induced by peroxynitrite, a potent physiological inorganic toxin. The present study has shown that SAG significantly inhibits single strand breaks in supercoiled plasmid DNA induced by synthesized peroxynitrite (ONOO(-)) and 3-morpholinosydnomine N-ethylcarbamide (SIN-1), a generator of peroxynitrite through the reaction between nitric oxide and superoxide anion. The formation of 8-hydroxy-2(')-deoxyguanosine in calf thymus DNA by peroxynitrite and SIN-1 was also significantly inhibited by SAG. The protective effect on peroxynitrite-mediated DNA damage was completely abolished by the reaction of SAG with N-ethylmaleimide, a chemical modification agent for the sulfhydryl group of proteins. These observations suggested that the sulfhydryl group of cysteines in SAG could react directly with peroxynitrite to prevent DNA damage.
authors.affiliation: Department of Biochemistry, College of Natural Sciences, Kyungpook National University, Taegu, Republic of Korea.
authors.forename: Sun Yee
authors.initials: SY
authors.lastname: Kim
authors.forename: Jin Hyup
authors.initials: JH
authors.lastname: Lee
authors.forename: Eun Sun
authors.initials: ES
authors.lastname: Yang
authors.forename: In Sup
authors.initials: IS
authors.lastname: Kil
authors.forename: Jeen-Woo
authors.initials: JW
authors.lastname: Park
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D003545:Cysteine / Q000187:drug effects; D004249:DNA Damage; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005033:Ethylmaleimide / Q000494:pharmacology; D006801:Humans; D008981:Molsidomine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors; D030421:Peroxynitrous Acid / Q000037:antagonists & inhibitors*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000494:pharmacology*; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D044767:Ubiquitin-Protein Ligases
chemical_list: D000975:Antioxidants; D016601:RNA-Binding Proteins; D013439:Sulfhydryl Reagents; D030421:Peroxynitrous Acid; C002385:linsidomine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D008981:Molsidomine; C118307:RNF7 protein, human; D044767:Ubiquitin-Protein Ligases; D003849:Deoxyguanosine; D003545:Cysteine; D005033:Ethylmaleimide