title: Copper-dependent interaction of glutaredoxin with the N termini of the copper-ATPases (ATP7A and ATP7B) defective in Menkes and Wilson diseases.
abstract: The P-type ATPases affected in Menkes and Wilson diseases, ATP7A and ATP7B, respectively, are key copper transporters that regulate copper homeostasis. The N termini of these proteins are critical in regulating their function and activity, and contain six copper-binding motifs MxCxxC. In this study, we describe the identification of glutaredoxin (GRX1) as an interacting partner of both ATP7A and ATP7B, confirmed by yeast two-hybrid technology and by co-immunoprecipitation from mammalian cells. The interaction required the presence of copper and intact metal-binding motifs. In addition, the interaction was related to the number of metal-binding domains available. GRX1 catalyses the reduction of disulphide bridges and reverses the glutathionylation of proteins to regulate and/or protect protein activity. We propose that GRX1 is essential for ATPase function and catalyses either the reduction of intramolecular disulphide bonds or the deglutathionylation of the cysteine residues within the CxxC motifs to facilitate copper-binding for subsequent transport.
authors.affiliation: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Vic. 3125, Australia.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Lim
authors.forename: Michael A
authors.initials: MA
authors.lastname: Cater
authors.forename: Julian F B
authors.initials: JF
authors.lastname: Mercer
authors.forename: Sharon
authors.initials: S
authors.lastname: La Fontaine
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D027682:Cation Transport Proteins / Q000378:metabolism*; D003300:Copper / Q000494:pharmacology*; D000073840:Copper-Transporting ATPases; D054477:Glutaredoxins; D006801:Humans; D010088:Oxidoreductases / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D027682:Cation Transport Proteins; D054477:Glutaredoxins; D003300:Copper; D010088:Oxidoreductases; D000251:Adenosine Triphosphatases; C081184:ATP7A protein, human; C000612464:ATP7B protein, human; D000073840:Copper-Transporting ATPases