title: How radiation kills cells: survival of Deinococcus radiodurans and Shewanella oneidensis under oxidative stress.
abstract: We have recently shown that Deinococcus radiodurans and other radiation resistant bacteria accumulate exceptionally high intracellular manganese and low iron levels. In comparison, the dissimilatory metal-reducing bacterium Shewanella oneidensis accumulates Fe but not Mn and is extremely sensitive to radiation. We have proposed that for Fe-rich, Mn-poor cells killed at radiation doses which cause very little DNA damage, cell death might be induced by the release of Fe(II) from proteins during irradiation, leading to additional cellular damage by Fe(II)-dependent oxidative stress. In contrast, Mn(II) ions concentrated in D. radiodurans might serve as antioxidants that reinforce enzymic systems which defend against oxidative stress during recovery. We extend our hypothesis here to include consideration of respiration, tricarboxylic acid cycle activity, peptide transport and metal reduction, which together with Mn(II) transport represent potential new targets to control recovery from radiation injury.
authors.affiliation: Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
authors.forename: Debabrota
authors.initials: D
authors.lastname: Ghosal
authors.forename: Marina V
authors.initials: MV
authors.lastname: Omelchenko
authors.forename: Elena K
authors.initials: EK
authors.lastname: Gaidamakova
authors.forename: Vera Y
authors.initials: VY
authors.lastname: Matrosova
authors.forename: Alexander
authors.initials: A
authors.lastname: Vasilenko
authors.forename: Amudhan
authors.initials: A
authors.lastname: Venkateswaran
authors.forename: Min
authors.initials: M
authors.lastname: Zhai
authors.forename: Heather M
authors.initials: HM
authors.lastname: Kostandarithes
authors.forename: Hassan
authors.initials: H
authors.lastname: Brim
authors.forename: Kira S
authors.initials: KS
authors.lastname: Makarova
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Wackett
authors.forename: James K
authors.initials: JK
authors.lastname: Fredrickson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Daly
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D034301:Deinococcus / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects*; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D018384:Oxidative Stress; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D020592:Shewanella / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D008345:Manganese; D007501:Iron