A new perspective on radiation resistance based on Deinococcus radiodurans.
In classical models of radiation toxicity, DNA is the molecule that is most affected by ionizing radiation (IR). However, recent data show that the amount of protein damage caused during irradiation of bacteria is better related to survival than to DNA damage. In this Opinion article, a new model is presented in which proteins are the most important target in the hierarchy of macromolecules affected by IR. A first line of defence against IR in extremely radiation-resistant bacteria might be the accumulation of manganese complexes, which can prevent the production of iron-dependent reactive oxygen species. This would allow an irradiated cell to protect sufficient enzymatic activity needed to repair DNA and survive.
Daly
Michael J
MJ
Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA. mdaly@usuhs.edu
D001426:Bacterial Proteins / Q000378:metabolism*; D004260:DNA Repair / Q000528:radiation effects; D034301:Deinococcus / Q000235:genetics / Q000502:physiology / Q000528:radiation effects*; D005798:Genes, Bacterial; D007259:Infrared Rays; D007501:Iron / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D050050:Protein Carbonylation / Q000502:physiology / Q000528:radiation effects; D011506:Proteins / Q000378:metabolism* / Q000528:radiation effects; D011836:Radiation Tolerance; D017382:Reactive Oxygen Species / Q000378:metabolism
D001426:Bacterial Proteins; D011506:Proteins; D017382:Reactive Oxygen Species; D008345:Manganese; D007501:Iron