title: A role for copper in protozoan grazing - two billion years selecting for bacterial copper resistance.
abstract: The Great Oxidation Event resulted in integration of soft metals in a wide range of biochemical processes including, in our opinion, killing of bacteria by protozoa. Compared to pressure from anthropologic copper contamination, little is known on impacts of protozoan predation on maintenance of copper resistance determinants in bacteria. To evaluate the role of copper and other soft metals in predatory mechanisms of protozoa, we examined survival of bacteria mutated in different transition metal efflux or uptake systems in the social amoeba Dictyostelium discoideum. Our data demonstrated a strong correlation between the presence of copper/zinc efflux as well as iron/manganese uptake, and bacterial survival in amoebae. The growth of protozoa, in turn, was dependent on bacterial copper sensitivity. The phagocytosis of bacteria induced upregulation of Dictyostelium genes encoding the copper uptake transporter p80 and a triad of Cu(I)-translocating PIB-type ATPases. Accumulated Cu(I) in Dictyostelium was monitored using a copper biosensor bacterial strain. Altogether, our data demonstrate that Cu(I) is ultimately involved in protozoan predation of bacteria, supporting our hypothesis that protozoan grazing selected for the presence of copper resistance determinants for about two billion years.
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Hao
authors.affiliation: Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Freja
authors.initials: F
authors.lastname: Lüthje
authors.affiliation: Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Regin
authors.initials: R
authors.lastname: Rønn
authors.affiliation: Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, TX, USA.
authors.forename: Nadezhda A
authors.initials: NA
authors.lastname: German
authors.affiliation: Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Xuanji
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Fuyi
authors.initials: F
authors.lastname: Huang
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA.
authors.forename: Javan
authors.initials: J
authors.lastname: Kisaka
authors.affiliation: Department of Chemistry, Western Michigan University, Kalamazoo, MI, USA.
authors.forename: David
authors.initials: D
authors.lastname: Huffman
authors.affiliation: Department of Botany and Microbiology, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Hend A
authors.initials: HA
authors.lastname: Alwathnani
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China.|J. Craig Venter Institute, La Jolla, CA, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rensing
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D001424:Bacterial Infections; D003300:Copper / Q000494:pharmacology*; D004023:Dictyostelium / Q000378:metabolism / Q000382:microbiology*; D004351:Drug Resistance; D019143:Evolution, Molecular; D010587:Phagocytosis / Q000187:drug effects; D015800:Protozoan Proteins / Q000378:metabolism
chemical_list: D015800:Protozoan Proteins; D003300:Copper