Similar to higher eukaryotes, the protist parasite T. brucei harbours several iron-containing proteins that regulate DNA and protein processing, oxidative stress defence and mitochondrial respiration. The synthesis of these proteins occurs either in the cytoplasm or within the mitochondrion. For mitochondrial iron cluster protein synthesis, iron needs to be transported across the solute impermeable mitochondrial membrane. In T. brucei we previously identified 24 mitochondrial carrier proteins (TbMCPs) sharing conserved structural and functional features with those from higher eukaryotes. One of these carriers (TbMCP17) displayed high similarity with the iron carriers MRS3, MRS4 from yeast and mitoferrin from mammals, insects and plants. In the present study we demonstrated that TbMCP17 functions as an iron carrier by complementation studies using MRS3/4-deficient yeast. Depletion of TbMCP17 in procyclic form T. brucei resulted in growth deficiency, increased sensitivity to iron deprivation, and lowered mitochondrial iron content. Taken together our results suggest that TbMCP17 functions as a mitochondrial iron transporter in the parasite T. brucei.

与高级真核生物相似，原生生物寄生虫布鲁氏菌（T. brucei）含有几种含铁蛋白质，它们调节DNA和蛋白质加工，氧化应激防御和线粒体呼吸作用。这些蛋白质的合成发生在细胞质中或线粒体内。对于线粒体铁簇蛋白的合成，需要将铁转运通过不溶质的线粒体膜。在布鲁氏菌中，我们先前鉴定了24个线粒体载体蛋白（Tb MCP），它们与来自高级真核生物的蛋白具有保守的结构和功能特征。这些载体之一（TbMCP17）与来自酵母的铁载体MRS3，MRS4和来自哺乳动物，昆虫和植物的米托铁蛋白具有高度相似性。在本研究中，我们通过使用MRS3 / 4缺陷型酵母的互补研究证明Tb MCP17作为铁载体。Tb MCP17的前环形式T. brucei的耗尽导致生长不足，对铁缺乏的敏感性增加和线粒体铁含量降低。总之我们的研究结果表明，铽MCP17作为寄生虫线粒体铁转运布氏锥虫。