Sequence, mapping and disruption of CCC2, a gene that cross‐complements the Ca²⁺‐sensitive phenotype of csg1 mutants and encodes a P‐type ATPase belonging to the Cu²⁺‐ATPase subfamily

We have isolated, sequenced, mapped and disrupted a gene, CCC2, from Saccharomyces cerevisiae. This gene displays non‐allelic complementation of the Ca²⁺‐sensitive phenotype conferred by the csg1 mutation. Analysis of the CCC2p amino acid sequence reveals that it encodes a member of the P‐type ATPase family and is most similar to a subfamily thought to consist of Cu²⁺ transporters, including the human genes that mutate to cause Wilson disease and Menkes disease. The ability of this gene, in two or more copies, to reverse the csg1 defect suggests that Ca²⁺‐induced death of csg1 mutant cells is related to Cu²⁺ metabolism. Cells without CCC2 require increased Cu²⁺ concentrations for growth. Therefore CCC2p may function to provide Cu²⁺ to a cellular compartment rather than in removal of excess of Cu²⁺. The sequence of CCC2 is available through GenBank under accession number L36317.