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Across the tree of life, radiation resistance is governed by antioxidant Mn, gauged by paramagnetic resonance.

Title: Across the tree of life, radiation resistance is governed by antioxidant Mn, gauged by paramagnetic resonance.
Name(s): Sharma, Ajay, author
Gaidamakova, Elena K, author
Grichenko, Olga, author
Matrosova, Vera Y, author
Hoeke, Veronika, author
Klimenkova, Polina, author
Conze, Isabel H, author
Volpe, Robert P, author
Tkavc, Rok, author
Gostinčar, Cene, author
Gunde-Cimerman, Nina, author
DiRuggiero, Jocelyne, author
Shuryak, Igor, author
Ozarowski, Andrew, author
Hoffman, Brian M, author
Daly, Michael J, author
Type of Resource: text
Genre: Journal Article
Date Issued: 2017-10-31
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: Despite concerted functional genomic efforts to understand the complex phenotype of ionizing radiation (IR) resistance, a genome sequence cannot predict whether a cell is IR-resistant or not. Instead, we report that absorption-display electron paramagnetic resonance (EPR) spectroscopy of nonirradiated cells is highly diagnostic of IR survival and repair efficiency of DNA double-strand breaks (DSBs) caused by exposure to gamma radiation across archaea, bacteria, and eukaryotes, including fungi and human cells. IR-resistant cells, which are efficient at DSB repair, contain a high cellular content of manganous ions (Mn) in high-symmetry (H) antioxidant complexes with small metabolites (e.g., orthophosphate, peptides), which exhibit narrow EPR signals (small zero-field splitting). In contrast, Mn ions in IR-sensitive cells, which are inefficient at DSB repair, exist largely as low-symmetry (L) complexes with substantially broadened spectra seen with enzymes and strongly chelating ligands. The fraction of cellular Mn present as H-complexes (H-Mn), as measured by EPR of live, nonirradiated Mn-replete cells, is now the strongest known gauge of biological IR resistance between and within organisms representing all three domains of life: Antioxidant H-Mn complexes, not antioxidant enzymes (e.g., Mn superoxide dismutase), govern IR survival. As the pool of intracellular metabolites needed to form H-Mn complexes depends on the nutritional status of the cell, we conclude that IR resistance is predominantly a metabolic phenomenon. In a cross-kingdom analysis, the vast differences in taxonomic classification, genome size, and radioresistance between cell types studied here support that IR resistance is not controlled by the repertoire of DNA repair and antioxidant enzymes.
Identifier: FSU_pmch_29042516 (IID), 10.1073/pnas.1713608114 (DOI), PMC5676931 (PMCID), 29042516 (RID), 29042516 (EID), 1713608114 (PII)
Keywords: DNA repair, DSB, Deinococcus, EPR, Ionizing radiation
Grant Number: R01 GM111097
Publication Note: This NIH-funded author manuscript originally appeared in PubMed Central at
Subject(s): Antioxidants/metabolism
Cell Line, Tumor
DNA Breaks, Double-Stranded
DNA Repair/physiology
Electron Spin Resonance Spectroscopy/methods
Gamma Rays
Jurkat Cells
Radiation, Ionizing
Superoxide Dismutase/metabolism
Persistent Link to This Record:
Host Institution: FSU
Is Part Of: Proceedings of the National Academy of Sciences of the United States of America.
Issue: iss. 44, vol. 114

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Sharma, A., Gaidamakova, E. K., Grichenko, O., Matrosova, V. Y., Hoeke, V., Klimenkova, P., … Daly, M. J. (2017). Across the tree of life, radiation resistance is governed by antioxidant Mn, gauged by paramagnetic resonance. Proceedings Of The National Academy Of Sciences Of The United States Of America. Retrieved from