title: A role of iron ions in the SOS DNA repair response induced by nitric oxide in Escherichia coli.
abstract: An induction of the SOS DNA repair response by physiological nitric oxide donors (dinitrosyl iron complexes (DNIC) with thiols and S-nitrosothiols (RSNO)) was studied in E. coli cells. DNIC with thiols were the most effective SOS-inducers. Being more toxic, RSNO mediated a similar response at 10-100 microM, but they were inactive at concentrations above 0.5 mM. Pretreatment of the cells with chelating agents, o-phenanthroline and picolinic acid, prevented induction of the SOS response by all NO-donors used and led to a decrease in the DNIC-type EPR signal that appeared after incubation of the cells with DNIC or S-nitrosoglutathione (GSNO). Analysis of these effects revealed a dual role of iron ions in reactivity and toxicity of the NO-donating agents. On one hand, they could stabilize GSNO in the form of less toxic DNIC, and, on the other hand, they took part in the formation of the SOS-inducing signal by NO-donating agents.
authors.affiliation: Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 117334, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Stupakova
authors.forename: I I
authors.initials: II
authors.lastname: Lobysheva
authors.forename: V D
authors.initials: VD
authors.lastname: Mikoyan
authors.forename: A F
authors.initials: AF
authors.lastname: Vanin
authors.forename: S V
authors.initials: SV
authors.lastname: Vasilieva
mesh_terms: D004260:DNA Repair / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D007501:Iron / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D013014:SOS Response, Genetics
chemical_list: D020030:Nitric Oxide Donors; D009569:Nitric Oxide; D007501:Iron