title: The zinc/thiolate redox biochemistry of metallothionein and the control of zinc ion fluctuations in cell signaling.
abstract: Free zinc ions are potent effectors of proteins. Their tightly controlled fluctuations ("zinc signals") in the picomolar range of concentrations modulate cellular signaling pathways. Sulfur (cysteine) donors generate redox-active coordination environments in proteins for the redox-inert zinc ion and make it possible for redox signals to induce zinc signals. Amplitudes of zinc signals are determined by the cellular zinc buffering capacity, which itself is redox-sensitive. In part by interfering with zinc and redox buffering, reactive species, drugs, toxins, and metal ions can elicit zinc signals that initiate physiological and pathobiochemical changes or lead to cellular injury when free zinc ions are sustained at higher concentrations. These interactions establish redox-inert zinc as an important factor in redox signaling. At the center of zinc/redox signaling are the zinc/thiolate clusters of metallothionein. They can transduce zinc and redox signals and thereby attenuate or amplify these signals.
authors: Department of Preventive Medicine & Community Health, The University of Texas Medical Branch, Division of Human Nutrition, 700 Harborside Drive, Galveston, TX 77555, USA.
authors: Artur
authors: A
authors: Krezel
authors: Qiang
authors: Q
authors: Hao
authors: Wolfgang
authors: W
authors: Maret
mesh_terms: D002413:Cations, Divalent / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry; D008667:Metalloproteins / Q000737:chemistry; D008668:Metallothionein / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D015398:Signal Transduction; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D008667:Metalloproteins; D008668:Metallothionein; D015032:Zinc; D003545:Cysteine