Characterization of the hCTR1 gene: Genomic organization, functional expression, and identification of a highly homologous processed gene

The human hCTR1 gene was originally identified by its ability to complement a yeast mutant deficient in high-affinity copper uptake (Zhou, B., Gitschi er, J., 1997. A human gene for copper uptake identified by complementation in yeast. Proc. Natl. Acad. Sci. USA 94, 7481-7486). Here, we have determin ed the DNA sequence of the exon-intron borders of the hCTR1 structural gene and report that the coding sequence is disrupted by three introns, all of which comply with the GT/AG rule. Furthermore, human fibroblasts, transfect ed with hCTR1 cDNA, were shown to have a dramatically increased capacity fo r Cu-64 uptake, indicating that the hCtr1 protein is functional in copper u ptake in human cells. In contrast, no evidence was found for involvement of the hCTR2 gene product in copper uptake. Finally, we have identified a hig hly homologous processed pseudogene, hCTR1 psi, which was localized to chro mosome 3q25/26. The processed gene was found to be transcribed, but due to a frame shift mutation, it only had the potential to encode a truncated pro tein of 95 amino acid residues, and cells transfected with hCTR1 psi DNA sh owed no increase of Cu-64 uptake. (C) 2000 Elsevier Science B.V. All rights reserved.