title: Localization of the Wilson's disease protein product to mitochondria.
abstract: Wilson's disease (WND) is an inherited disorder of copper homeostasis characterized by abnormal accumulation of copper in several tissues, particularly in the liver, brain, and kidney. The disease-associated gene encodes a copper-transporting P-type ATPase, the WND protein, the subcellular location of which could be regulated by copper. We demonstrate that the WND protein is present in cells in two forms, the 160-kDa and the 140-kDa products. The 160-kDa product was earlier shown to be targeted to trans-Golgi network. The 140-kDa product identified herein is located in mitochondria as evidenced by the immunofluorescent staining of HepG2 cells with specific mitochondria markers and polyclonal antibody directed against the C terminus of the WND molecule. The mitochondrial location for the 140-kDa WND product was confirmed by membrane fractionation and by analysis of purified human mitochondria. The antibody raised against a repetitive sequence in the N-terminal portion of the WND molecule detects an additional 16-kDa protein, suggesting that the 140-kDa product was formed after proteolytic cleavage of the full-length WND protein at the N terminus. Thus, the WND protein is a P-type ATPase with an unusual subcellular localization. The mitochondria targeting of the WND protein suggests its important role for copper-dependent processes taking place in this organelle.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland, OR 97201, USA. lutsenko@ohsu.edu
authors.forename: S
authors.initials: S
authors.lastname: Lutsenko
authors.forename: M J
authors.initials: MJ
authors.lastname: Cooper
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism*; D027682:Cation Transport Proteins; D003300:Copper / Q000378:metabolism; D000073840:Copper-Transporting ATPases; D006527:Hepatolenticular Degeneration / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D002352:Carrier Proteins; D027682:Cation Transport Proteins; D003300:Copper; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases