CCC1 Is a Transporter That Mediates Vacuolar Iron Storage in Yeast

• Published in: The Journal of biological chemistry Vol. 276; no. 31; pp. 29515 - 29519
• Main Authors: Li, L, Chen, O S, McVey Ward, D, Kaplan, J
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 03.08.2001
• Subjects: beta-Galactosidase - metabolism; Cation Transport Proteins; CCC1 gene; Cell Division; Ceruloplasmin - genetics; Ceruloplasmin - metabolism; Cytosol - metabolism; DNA Primers; end4 gene; FET4 gene; Fungal Proteins - genetics; Fungal Proteins - metabolism; Gene Deletion; Genes, Reporter; Iron - metabolism; Kinetics; Manganese - metabolism; Recombinant Fusion Proteins - metabolism; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins; transporters; Vacuoles - metabolism
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M103944200

The budding yeast Saccharomyces cerevisiae can grow for generations in the absence of exogenous iron, indicating a capacity to store intracellular iron. As cells can accumulate iron by endocytosis we studied iron metabolism in yeast that were defective in endocytosis. We demonstrated that endocytosis-defective yeast ( Δend4 ) can store iron in the vacuole, indicating a transfer of iron from the cytosol to the vacuole. Using several different criteria we demonstrated that CCC1 encodes a transporter that effects the accumulation of iron and Mn 2+ in vacuoles. Overexpression of CCC1, which is localized to the vacuole , lowers cytosolic iron and increases vacuolar iron content. Conversely, deletion of CCC1 results in decreased vacuolar iron content and decreased iron stores, which affect cytosolic iron levels and cell growth. Furthermore Δccc1 cells show increased sensitivity to external iron. The sensitivity to iron is exacerbated by ectopic expression of the iron transporter FET4 . These results indicate that yeast can store iron in the vacuole and that CCC1 is involved in the transfer of iron from the cytosol to the vacuole.