FDX1 Is Required for the Biogenesis of Mitochondrial Cytochrome c Oxidase in Mammalian Cells.
FDX1 Is Required for the Biogenesis of Mitochondrial Cytochrome c Oxidase in Mammalian Cells.
复制标题
FDX1 是哺乳动物细胞中线粒体细胞色素 c 氧化酶的生物发生所必需的。
DOI：
10.1016/j.jmb.2023.168317
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发表时间：
2023
影响因子：
5.6
通讯作者：
Gohil,VishalM
中科院分区：
文献类型：
--
作者：
Zulkifli,Mohammad;Okonkwo,AdrianaU;Gohil,VishalM
铁氧还蛋白(FDX)是进化上保守的铁-硫(Fe-S)蛋白，在多种代谢途径中作为电子传递蛋白发挥作用。哺乳动物线粒体含有两种铁氧还蛋白，即FDX1和FDX2，它们在结构上高度相似，但在功能上有所不同。以前的研究已经证实了FDX2在铁-S团簇的生物发生中的独特作用；然而，FDX1在体内似乎有多个靶点，其中一些是最近才出现的。利用CRISPR-Cas9在大鼠心肌细胞系中的功能丧失研究，我们证明了FDX1在线粒体呼吸和能量产生中的基本需求。我们将线粒体呼吸减少归因于细胞色素氧化酶(CcO)的丰度和组装的特定减少，CcO是线粒体的一种血红素-铜氧化酶，也是线粒体呼吸链的末端酶。FDX1基因敲除细胞的铜和HEMA/A3水平降低，这是CcO酶复合体成熟所必需的。补充铜未能挽救CcO的生物发生，但过表达血红素合成酶COX15，部分挽救了FDX1基因敲除细胞中COX1的丰度。这一发现将FDX1的功能与半生物合成联系起来，并将其置于CcO生物发生的COX15上游，就像它的祖先酵母同源物一样。综上所述，我们的工作已经确定FDX1是哺乳动物细胞中一个关键的CcO生物发生因子。
Ferredoxins (FDXs) are evolutionarily conserved iron-sulfur (Fe-S) proteins that function as electron transfer proteins in diverse metabolic pathways. Mammalian mitochondria contain two ferredoxins, FDX1 and FDX2, which share a high degree of structural similarity but exhibit different functionalities. Previous studies have established the unique role of FDX2 in the biogenesis of Fe-S clusters; however, FDX1 seems to have multiple targetsin vivo, some of which are only recently emerging. Using CRISPR-Cas9-based loss-of-function studies in rat cardiomyocyte cell line, we demonstrate an essential requirement of FDX1 in mitochondrial respiration and energy production. We attribute reduced mitochondrial respiration to a specific decrease in the abundance and assembly of cytochromecoxidase (CcO), a mitochondrial heme-copper oxidase and the terminal enzyme of the mitochondrial respiratory chain. FDX1 knockout cells have reduced levels of copper and hemea/a3,factors that are essential for the maturation of the CcO enzyme complex. Copper supplementation failed to rescue CcO biogenesis, but overexpression of hemeasynthase, COX15, partially rescued COX1 abundance in FDX1 knockout cells. This finding links FDX1 function to hemeabiosynthesis, and places it upstream of COX15 in CcO biogenesis like its ancestral yeast homolog. Taken together, our work has identified FDX1 as a critical CcO biogenesis factor in mammalian cells.