title: An expanding range of functions for the copper chaperone/antioxidant protein Atox1.
abstract: CONCLUSIONS
  Antioxidant protein 1 (Atox1 in human cells) is a copper chaperone for the copper export pathway with an essential role in cellular copper distribution. In vitro, Atox1 binds and transfers copper to the copper-transporting ATPases, stimulating their catalytic activity. Inactivation of Atox1 in cells inhibits maturation of secreted cuproenzymes as well as copper export from cells.
  
  
  BACKGROUND
  Accumulating data suggest that cellular functions of Atox1 are not limited to its copper-trafficking role and may include storage of labile copper, modulation of transcription, and antioxidant defense. The conserved metal binding site of Atox1, CxGC, differs from the metal-binding sites of copper-transporting ATPases and has a physiologically relevant redox potential that equilibrates with the GSH:GSSG pair.
  
  
  RESULTS
  Tight relationship appears to exist between intracellular copper levels and glutathione (GSH) homeostasis. The biochemical properties of Atox1 place it at the intersection of cellular networks that regulate copper distribution and cellular redox balance. Mechanisms through which Atox1 facilitates copper export and contributes to oxidative defense are not fully understood.
  
  
  CONCLUSIONS
  The current picture of cellular redox homeostasis and copper physiology will be enhanced by further mechanistic studies of functional interactions between the GSH:GSSG pair and copper-trafficking machinery.
authors.affiliation: Department of Physiology, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Hatori
authors.forename: Svetlana
authors.initials: S
authors.lastname: Lutsenko
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism; D001692:Biological Transport; D027682:Cation Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D000079922:Copper Transport Proteins; D000073840:Copper-Transporting ATPases; D006801:Humans; D056511:Metallochaperones / Q000737:chemistry / Q000378:metabolism*; D018832:Molecular Chaperones; D010084:Oxidation-Reduction
chemical_list: C474500:ATOX1 protein, human; D000975:Antioxidants; D027682:Cation Transport Proteins; D000079922:Copper Transport Proteins; D056511:Metallochaperones; D018832:Molecular Chaperones; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases