Frascati-mediated Mitochondrial Metabolism

本提案的目的是鉴定和表征线粒体中涉及的新蛋白质， 通过mRNA测序（RNAseq）从区分胎儿肝脏群体中鉴定铁/血红素代谢 和生物信息学方法。血红素作为血红素蛋白质中的辅基，用于广泛的 红细胞中血红蛋白的合成是最重要的细胞过程，其中最为人所知的是血红蛋白的合成。尽管 我们对胞质铁运输和原-白藜芦醇生物合成的理解的进展， 特别是，对于涉及铁从内体排出到内体的组分， 铁/血红素在线粒体内的运输，以及血红素从线粒体的最终输出， 线粒体，用于其并入血红蛋白中。近年来，我们已经确定了 lfrn 1（lfrn 1，Slc 25 a37）铁转运蛋白及其与其他线粒体蛋白、Abcbl 0和 铁螯合酶，在线粒体铁的获取及其在血红素合成中的利用。以试图 确定额外的，未知的成分重要的血红素合成，我们筛选了数千个 基因的微阵列，这些基因与先前已知的血红素紧密共表达和共调控， 生物合成基因，以确定潜在的有趣的，新的候选基因。这些后续研究 斑马鱼中的候选基因显示，使用反义吗啉代， 导致了所有病例的严重贫血作为补充，我们最近分析了 表达具有预测的跨膜基序、转运蛋白功能或定位于 线粒体，其通过RNAseq分析从分化的胎肝细胞中鉴定。我们 鉴定了9个额外的强诱导基因，其在红系铁/血红素代谢中的功能尚未被证实。 以前研究过。我们建议研究这9个基因的表达和功能丧失表型， 结构基因（c20 orf 108，Snx 3，Slc 43 a1，Slc 43 a3，Slc 7a 5，Ehbplll，Tmcc 2，Slc 38 a5，Tmem 14 c） 斑马鱼和哺乳动物细胞。特别是，我们计划将重点放在这些新发现的基因之一， 这两个生物信息学筛选，Tmem 14 c，一个未知功能的小线粒体膜蛋白。 相关性（参见说明）： 阐明这8个结构蛋白的功能，Tmem 14 c及其相互作用蛋白伴侣可能提供 深入了解线粒体血红素代谢中未知的步骤，并为探索 铁/血红素代谢和红细胞生成的人类疾病。

The objectives of this proposal are to identify and characterize novel proteins involved in mitochondrial iron/heme metabolism identified from differentiating fetal liver population by mRNA sequencing (RNAseq) and bioinformatics approaches. Heme serves as a prosthetic group in hemo-proteins for a wide array of crucial cellular processes, and of these, hemoglobin synthesis in red cells is the most well known. Despite advances in our understanding of cytosolic iron trafficking and proto-prophyrin biosynthesis, significant gaps remain, especially, with respect to components involving the egress of iron from the endosomes to the mitochondria, the trafficking of iron/heme within the mitochondria, and the eventual export of heme from the mitochondria for its incorporation in hemoglobin. In recent years, we have characterized the role ofthe l\/litoferrin1 (l\/lfrn1, Slc25a37) iron importer and its interaction with other mitochondrial proteins, AbcblO and ferrochelatase, in the acquisition of mitochondrial iron and its utilization in heme synthesis. In an attempt to dentify additional, unknown components important for heme synthesis, we screened thousands of microarrays for genes that were tightly co-expressed and co-regulated with previously known heme biosynthesis genes to identify potentially interesting, novel candidate genes. Follow up studies of these candidate genes in the zebrafish showed that gene-specific knockdown, using anti-sense morpholinos, resulted in profound anemia in all cases. In a complementary approach, we recently analyzed the expression of structural proteins with predicted transmembrane motifs, transporter function, or localization to the mitochondria, which were identified by RNAseq analysis from differentiating fetal liver cells. We identified 9 additional strongly induced genes, whose function in erythroid iron/heme metabolism has not been previously studied. We propose to study the expression and loss-of-function phenotype of these 9 structural genes (c20orf108, Snx3, Slc43a1, Slc43a3, Slc7a5, Ehbplll, Tmcc2, Slc38a5, Tmem14c) in the zebrafish and mammalian cells. In particular, we plan to focus on one of these newly identified genes from the two bioinformatics screens, Tmem14c, a small mitochondrial membrane protein of unknown function. RELEVANCE (See instructions): Elucidating the function of these 8 structural proteins, Tmem14c and its interacting protein partners may give insight into unknown steps in mitochondrial heme metabolism and provide new genetic tools for exploring human disorders of iron/heme metabolism and erythropoiesis.