Characterization of a heavy metal ion transporter in the lysosomal membrane.
Lysosomes are thought to play a role in various aspects of heavy metal metabolism. In the present study we demonstrate for the first time the presence of a heavy metal ion transport protein in the lysosomal membrane. Uptake of radioactive silver both in highly purified lysosomal membrane vesicles and in purified intact lysosomes showed the typical kinetics of a carrier-mediated process. This transport was stimulated by ATP hydrolysis, and showed specificity for Ag+, Cu2+, and Cd2+. All biochemical properties of this lysosomal metal ion transporter could classify it as a heavy metal transporting P-type ATPase. Long Evans Cinnamon (LEC) rats, an animal model for the copper transport disorder Wilson disease, showed normal lysosomal silver transport.
Department of Clinical Genetics, Erasmus University, Rotterdam, The Netherlands.
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D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002104:Cadmium / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002458:Cell Fractionation; D003300:Copper / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008247:Lysosomes / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D017208:Rats, Wistar; D012265:Ribonucleotides / Q000494:pharmacology; D012834:Silver / Q000378:metabolism*; D013379:Substrate Specificity
D002352:Carrier Proteins; D012265:Ribonucleotides; D002104:Cadmium; D012834:Silver; D003300:Copper; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases