%0 Journal Article
%T How does hormesis impact biology, toxicology, and medicine?
%A Edward J. Calabrese
%A Mark P. Mattson
%J Archive of "NPJ Aging and Mechanisms of Disease".
%D 2017
%R 10.1038/s41514-017-0013-z
%X Evolutionary hormesis-based adaptations that enabled organisms to survive and flourish in the presence of toxic metals. The solubilization of iron and copper in rocks results in the formation of ions (Fe2+ and Cu+) that can be highly toxic to cells. During respiration (oxidative phosphorylation), cells generate hydrogen peroxide (H2O2). Interaction of H2O2 with Fe2+ or Cu+ results in the generation of the highly destructive hydroxyl free radical (OH£¿.), which can kill cells by damaging DNA, proteins, and membrane lipids. Beginning very early in the evolution of life, organisms evolved proteins to protect themselves against Fe2+ or Cu+ toxicity. The proteins include those that sequester the metal ions or expel them from the cell. In addition, various iron- or copper-dependent enzymes evolved that used the redox properties of these elements to their advantage. Examples of proteins involved in iron and copper metabolism are shown. FRO7 ferric chelate reductase oxidase 7; P1C1 permease in chloroplasts; PAM peptidylglycine-alpha-amidating monooxygenase; V1T1 vacuolar iron transporter 1. All images in the figure were obtained from Wikimedia Commons under the Creative Commons copyright 4.0 International, 2.0 Generic, and Share Alike 2.5 Generic (CC-BY) license, and GNU Free Documentation 1.2 licens
%U https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5601424/