title: Effect of the space environment on the induction of DNA-repair related proteins and recovery from radiation damage.
abstract: Recovery of bacterial cells from radiation damage and the effects of microgravity were examined in an STS-79 Shuttle/Mir Mission-4 experiment using the extremely radioresistant bacterium Deinococcus radiodurans. The cells were irradiated with gamma rays before the space flight and incubated on board the Space-Shuttle. The survival of the wild type cells incubated in space increased compared with the ground controls, suggesting that the recovery of this bacterium from radiation damage was enhanced under microgravity. No difference was observed for the survival of radiosensitive mutant rec30 cells whether incubated in space or on the ground. The amount of DNA-repair related RecA protein induced under microgravity was similar to those of ground controls, however, induction of PprA protein, the product of a newly found gene related to the DNA repair mechanism of D. radiodurans, was enhanced under microgravity compared with ground controls.
authors.affiliation: Takasaki Radiation Chemistry Research Establishment, Japan Atomic Energy Research Institute.
authors.forename: Y
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Kikuchi
authors.forename: I
authors.initials: I
authors.lastname: Narumi
mesh_terms: D001426:Bacterial Proteins; D003037:Cobalt Radioisotopes; D004249:DNA Damage; D004260:DNA Repair; D004269:DNA, Bacterial / Q000528:radiation effects*; D005720:Gamma Rays; D005798:Genes, Bacterial; D006095:Gram-Positive Cocci / Q000166:cytology / Q000235:genetics / Q000528:radiation effects*; D011836:Radiation Tolerance; D011938:Rec A Recombinases; D015203:Reproducibility of Results; D013026:Space Flight; D014893:Weightlessness
chemical_list: D001426:Bacterial Proteins; D003037:Cobalt Radioisotopes; D004269:DNA, Bacterial; D011938:Rec A Recombinases