TY - JOUR
T1 - The Copper Toxicosis Gene Product Murr1 Directly Interacts with the Wilson Disease Protein
AU - Tao, Ting Y.
AU - Liu, Fengli
AU - Klomp, Leo
AU - Wijmenga, Cisca
AU - Gitlin, Jonathan D.
PY - 2003/10/24
Y1 - 2003/10/24
N2 - Copper toxicosis in Bedlington terriers is an autosomal recessive disorder characterized by excessive hepatic copper accumulation in association with a marked decrease in biliary copper excretion. Recent genetic data have revealed that MURR1, a single copy gene on dog chromosome 10q26, is mutated in this disorder. This gene encodes a 190-amino acid open reading frame of unknown function that is highly conserved in vertebrate species. The Wilson disease protein is a copper transporting ATPase shown to play a critical role in biliary copper excretion. Here we demonstrate that the Wilson disease protein directly interacts with the human homologue of Murr1 in vitro and in vivo and that this interaction is mediated via the copper binding, amino terminus of this ATPase. Importantly, this interaction is specific for this copper transporter, a finding consistent with the observation that impaired copper homeostasis in affected terriers is confined to the liver. Our findings reveal involvement of Murr1 in the defined pathway of hepatic biliary copper excretion, suggest a potential mechanism for Murr1 function in this process, and provide biochemical evidence in support of the proposed role of the MURR1 gene in hepatic copper toxicosis.
AB - Copper toxicosis in Bedlington terriers is an autosomal recessive disorder characterized by excessive hepatic copper accumulation in association with a marked decrease in biliary copper excretion. Recent genetic data have revealed that MURR1, a single copy gene on dog chromosome 10q26, is mutated in this disorder. This gene encodes a 190-amino acid open reading frame of unknown function that is highly conserved in vertebrate species. The Wilson disease protein is a copper transporting ATPase shown to play a critical role in biliary copper excretion. Here we demonstrate that the Wilson disease protein directly interacts with the human homologue of Murr1 in vitro and in vivo and that this interaction is mediated via the copper binding, amino terminus of this ATPase. Importantly, this interaction is specific for this copper transporter, a finding consistent with the observation that impaired copper homeostasis in affected terriers is confined to the liver. Our findings reveal involvement of Murr1 in the defined pathway of hepatic biliary copper excretion, suggest a potential mechanism for Murr1 function in this process, and provide biochemical evidence in support of the proposed role of the MURR1 gene in hepatic copper toxicosis.
UR - http://www.scopus.com/inward/record.url?scp=0142149219&partnerID=8YFLogxK
U2 - 10.1074/jbc.C300391200
DO - 10.1074/jbc.C300391200
M3 - Article
C2 - 12968035
AN - SCOPUS:0142149219
SN - 0021-9258
VL - 278
SP - 41593
EP - 41596
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 43
ER -