Caenorhabditis elegans cDNA for a Menkes/Wilson disease gene homologue and its function in a yeast CCC2 gene deletion mutant

The full-length cDNA coding for a putative copper transporting P-type ATPase (Cu²⁺-ATPase) was cloned from Caenorhabditis elegans. The putative Cu²⁺-ATPase is a 1,238-amino acid protein, and highly homologous to the Menkes and Wilson disease gene products mutations of which are responsible for human defects of copper metabolism. The Saccharomyces cerevisiae mutant with a disrupted CCC2 gene (yeast Menkes/Wilson disease gene homologue) was rescued by the cDNA for the C. elegans Cu²⁺-ATPase but not by the cDNA with an Asp-786 (an invariant phosphorylation site) to Asn mutation, suggesting that the C. elegans Cu²⁺-ATPase functions as a copper transporter in yeast. The expressed C. elegans protein was detected in yeast vacuolar membranes by immunofluorescence microscopy. The yeast expression system may facilitate further studies on copper transporting P-type ATPases.