title: Role of glutaredoxin1 and glutathione in regulating the activity of the copper-transporting P-type ATPases, ATP7A and ATP7B.
abstract: The copper-transporting P-type ATPases (Cu-ATPases), ATP7A and ATP7B, are essential for the regulation of intracellular copper homeostasis. In this report we describe new roles for glutathione (GSH) and glutaredoxin1 (GRX1) in Cu homeostasis through their regulation of Cu-ATPase activity. GRX1 is a thiol oxidoreductase that catalyzes the reversible reduction of GSH-mixed disulfides to their respective sulfhydryls (deglutathionylation). Here, we demonstrated that glutathionylation of the Cu-ATPases and their interaction with GRX1 were affected by alterations in Cu levels. The data support our hypothesis that the Cu-ATPases serve as substrates for Cu-dependent GRX1-mediated deglutathionylation. This in turn liberates the Cu-ATPase cysteinyl thiol groups for Cu binding and transport. GSH depletion experiments led to reversible inhibition of the Cu-ATPases that correlated with effects on intracellular Cu levels and GRX1 activity. Finally, knockdown of GRX1 expression resulted in an increase in intracellular Cu accumulation. Together, these data directly implicate GSH and GRX1 with important new roles in redox regulation of the Cu-ATPases, through modulation of Cu binding by the Cu-ATPase cysteine motifs.
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: William C J
authors.initials: WCJ
authors.lastname: Singleton
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: Kelly T
authors.initials: KT
authors.lastname: McInnes
authors.affiliation: Mental Health Research Institute of Victoria, Parkville, 3052 Victoria, Australia.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Cater
authors.affiliation: Centre for Reproduction and Development, Monash Institute of Medical Research, Clayton, 3168 Victoria, Australia.
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Winnall
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: Ross
authors.initials: R
authors.lastname: McKirdy
authors.affiliation: Department of Pathology, University of Sydney, Sydney, 2006 New South Wales, Australia.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: Philip E
authors.initials: PE
authors.lastname: Taylor
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: Bi-Xia
authors.initials: BX
authors.lastname: Ke
authors.affiliation: Department of Pathology, University of Sydney, Sydney, 2006 New South Wales, Australia.
authors.forename: Des R
authors.initials: DR
authors.lastname: Richardson
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia.
authors.forename: Julian F B
authors.initials: JFB
authors.lastname: Mercer
authors.affiliation: Strategic Research Centre for Molecular and Medical Research and Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, 3125 Victoria, Australia. Electronic address: sharon.lafontaine@deakin.edu.au.
authors.forename: Sharon
authors.initials: S
authors.lastname: La Fontaine
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D016466:CHO Cells; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D000073840:Copper-Transporting ATPases; D006224:Cricetinae; D003412:Cricetulus; D055785:Gene Knockdown Techniques; D054477:Glutaredoxins / Q000235:genetics / Q000378:metabolism*; D005978:Glutathione / Q000235:genetics / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D011485:Protein Binding / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology*
chemical_list: D027682:Cation Transport Proteins; D054477:Glutaredoxins; D003300:Copper; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; C000612464:ATP7B protein, human; D000073840:Copper-Transporting ATPases; D005978:Glutathione