Extremophiles

, Volume 17, Issue 3, pp 485–497

Effects of intracellular Mn on the radiation resistance of the halophilic archaeon Halobacterium salinarum

Authors

  • Kimberly M. Webb
    • Department of BiologyJohns Hopkins University
  • Jerry Yu
    • Department of BiologyJohns Hopkins University
  • Courtney K. Robinson
    • Department of BiologyJohns Hopkins University
  • Tomiya Noboru
    • Department of BiologyJohns Hopkins University
  • Yuan C. Lee
    • Department of BiologyJohns Hopkins University
    • Department of BiologyJohns Hopkins University
Original Paper

DOI: 10.1007/s00792-013-0533-9

Cite this article as:
Webb, K.M., Yu, J., Robinson, C.K. et al. Extremophiles (2013) 17: 485. doi:10.1007/s00792-013-0533-9

Abstract

Ionizing radiation (IR) is of particular interest in biology because its exposure results in severe oxidative stress to the cell’s macromolecules. Our recent work with extremophiles supports the idea that IR resistance is most likely achieved by a metabolic route, effected by manganese (Mn) antioxidants. Biochemical analysis of “super-IR resistant” mutants of H. salinarum, evolved over multiple cycles of exposure to high doses of IR, confirmed the key role for Mn antioxidants in the IR resistance of this organism. Analysis of the proteome of H. salinarum “super-IR resistant” mutants revealed increased expression for proteins involved in energy metabolism, replenishing the cell with reducing equivalents depleted by the oxidative stress inflicted by IR. Maintenance of redox homeostasis was also activated by the over-expression of coenzyme biosynthesis pathways involved in redox reactions. We propose that in H. salinarum, increased tolerance to IR is a combination of metabolic regulatory adjustments and the accumulation of Mn-antioxidant complexes.

Keywords

Halophiles Mn2+ Oxidative stress Ionizing radiation Proteomics

Supplementary material

792_2013_533_MOESM1_ESM.docx (427 kb)
Supplementary material 1 (DOCX 478 kb)
792_2013_533_MOESM2_ESM.pdf (65 kb)
Supplementary material 2 (PDF 64 kb)
792_2013_533_MOESM3_ESM.pdf (182 kb)
Supplementary material 3 (PDF 182 kb)

Copyright information

© Springer Japan 2013