Title: Uranium directly interacts with the DNA repair protein poly (ADP-ribose) polymerase 1.
Authors: Zhou, Xixi; Xue, Bingye; Medina, Sebastian; Burchiel, Scott W; Liu, Ke Jian
Published In Toxicol Appl Pharmacol, (2021 01 01)
Abstract: People living in southwest part of United States are exposed to uranium (U) through drinking water, air, and soil. U is radioactive, but independent of this radioactivity also has important toxicological considerations as an environmental metal. At environmentally relevant concentrations, U is both mutagenic and carcinogenic. Emerging evidence shows that U inhibits DNA repair activity, but how U interacts with DNA repair proteins is still largely unknown. Herein, we report that U directly interacts with the DNA repair protein, Protein Poly (ADP-ribose) Polymerase 1 (PARP-1) through direct binding with the zinc finger motif, resulting in zinc release from zinc finger and DNA binding activity loss of the protein. At the peptide level, instead of direct competition with zinc ion in the zinc finger motif, U does not show thermodynamic advantages over zinc. Furthermore, zinc pre-occupied PARP-1 zinc finger is insensitive to U treatment, but U bound to PARP-1 zinc finger can be partially replaced by zinc. These results provide mechanistic basis on molecular level to U inhibition of DNA repair.
PubMed ID:
33279515
MeSH Terms: Amino Acid Sequence; Cells, Cultured; DNA Repair/physiology*; DNA Repair/radiation effects*; Environmental Exposure/adverse effects; Humans; Infant, Newborn; Keratinocytes/metabolism; Keratinocytes/radiation effects; Poly (ADP-Ribose) Polymerase-1/genetics; Poly (ADP-Ribose) Polymerase-1/metabolism*; Poly (ADP-Ribose) Polymerase-1/radiation effects*; Protein Binding/drug effects; Protein Binding/physiology; Uranium/metabolism*; Uranium/toxicity*