Complementation of Saccharomyces cerevisiae ccc2 mutant by a putative P1B-ATPase from Brassica napus supports a copper-transporting function

Copper transport across membranes plays an important role in plant growth and survival. P-1B-type ATPases participate in transmembrane transport of copper in various organisms. A Brassica napus cDNA (BnRAN1) encoding a putative Cu2+-ATPase was cloned in this study. A complementation assay demonstrated that the protein encoded by this cDNA could functionally replace Ccc2p, a Saccharomyces cerevisiae Cu2+-ATPase, rescuing growth of ccc2 mutant under iron-limited conditions. Our results suggest that this rescue likely resulted from restoration of copper delivery, mediated by BnRAN1, to Fet3p. This study is amongst the first to demonstrate that a putative plant P-1B-ATPase is functional and to examine its substrate specificity. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.