Project 5 Frascati-mediated Mitochondrial Metabolism, Barry Paw

项目摘要 本提案的总体目标是鉴定和表征红细胞系中涉及的新蛋白质， 铁/血红素代谢红细胞生成是细胞增殖和合成单个 蛋白质血红蛋白因此，需要大量的铁和血红素来有效地 在发展中的非洲国家贩卖。尽管我们对细胞外铁的理解有了进步 运输和原卟啉生物合成，仍然存在重大差距，特别是在组分方面 包括铁从内体到线粒体的出口，铁/血红素在线粒体内的运输， 线粒体，原卟啉生成所需的转运蛋白，促进细胞内 铁/血红素的运输，以及血红素从线粒体的最终输出，以将其并入 血红蛋白。利用遗传学和生物信息学的互补方法，从转录谱，我们 先前鉴定的几种蛋白质，如线粒体铁蛋白1（Mfrn 1）、分选连接蛋白3（Snx 3）、Tmem 14 c、Lat 3和 clpx 1作为细胞内运输铁、血红素和营养物质的新组分，对红细胞至关重要， 发展虽然转录谱提供了见解，我们表明，翻译后， 在铁和血红素相关蛋白的表达和功能中， 新陈代谢.使用定量质谱，我们检测了线粒体蛋白质组的变化， 红系细胞经历成熟。我们鉴定了几种溶质载体和跨膜蛋白， 在红细胞生成中的功能以前没有被归因于由血红蛋白化诱导的。我们 建议研究这7个候选基因的表达和功能丧失表型（目的1）。在 特别地，我们计划将先前确定的基因Fam 210 b（c20 orf 108）及其相互作用的红色伴侣作为重点 细胞发育（目标2）。这些结构基因的功能阐明将扩大我们的知识， 细胞内溶质、铁和血红素运输中对红细胞生成至关重要的未知额外步骤。结果 我们的建议将为我们提供新的遗传工具，以探索人类贫血症。

PROJECT SUMMARY The overall objective of this proposal is to identify and characterize novel proteins involved in erythroid iron/heme metabolism. Erythropoiesis is a massive exercise in cellular proliferation and synthesis of a single protein, hemoglobin. As a consequence, there is a tremendous demand for iron and heme to be efficiently trafficked within the developing erythron. Despite advances in our understanding of extra-cellular iron trafficking and proto-porphyrin 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, the transporters required for proto-porphyrin genesis, the cofactors that facilitate the intracellular trafficking of iron/heme, and the eventual export of heme from the mitochondria for its incorporation in hemoglobin. Using complementary approaches of genetics and bioinformatics from transcriptional profiling, we previously identified several proteins, such as Mitoferrin1 (Mfrn1), Sorting Nexin3 (Snx3), Tmem14c, Lat3, and Clpx1, as new components in the intracellular trafficking of iron, heme and nutrients crucial to red cell development. Although transcriptional profiling as provided insights, we showed that post-translational mechanisms play equally critical roles in the expression and function of proteins involved in iron and heme metabolism. Using quantitative mass spectrometry, we examined changes in the mitochondrial proteome as erythroid cells undergo maturation. We identified several solute carriers and transmembrane proteins, whose function in erythropoiesis have not been previously ascribed, that were induced with hemoglobinization. We propose to study the expression and loss-of-function phenotype of these 7 candidate genes (Aim 1). In particular, we plan to focus previously identified gene, Fam210b (c20orf108), and its interacting partners in red cell development (Aim 2). Functional elucidation of these structural genes will expand our knowledge into the unknown additional steps in intracellular solute, iron and heme trafficking crucial for erythropoiesis. The results of our proposal will provide us with new genetic tools to explore human disorders of anemias.