Overlap of copper and iron uptake systems in mitochondria in Saccharomyces cerevisiae |
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Authors: | Katherine E Vest Jing Wang Micah G Gammon Margaret K Maynard Olivia L White Jai A Cobine Wilkerson K Mahone Paul A Cobine |
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Institution: | 1.Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA;2.College of Charleston, Charleston, SC 29424, USA |
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Abstract: | In Saccharomyces cerevisiae, the mitochondrial carrier family protein Pic2 imports copper into the matrix. Deletion of PIC2 causes defects in mitochondrial copper uptake and copper-dependent growth phenotypes owing to decreased cytochrome c oxidase activity. However, copper import is not completely eliminated in this mutant, so alternative transport systems must exist. Deletion of MRS3, a component of the iron import machinery, also causes a copper-dependent growth defect on non-fermentable carbon. Deletion of both PIC2 and MRS3 led to a more severe respiratory growth defect than either individual mutant. In addition, MRS3 expressed from a high copy number vector was able to suppress the oxygen consumption and copper uptake defects of a strain lacking PIC2. When expressed in Lactococcus lactis, Mrs3 mediated copper and iron import. Finally, a PIC2 and MRS3 double mutant prevented the copper-dependent activation of a heterologously expressed copper sensor in the mitochondrial intermembrane space. Taken together, these data support a role for the iron transporter Mrs3 in copper import into the mitochondrial matrix. |
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Keywords: | copper iron cytochrome c oxidase mitochondrial carrier family |
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