Frascati: mitochondrial transporter and erythropoiesis

描述(申请人提供)：本提案的目的是了解一种新的线粒体溶质转运蛋白(SLC25)Frascati在脊椎动物红细胞生成和铁代谢中的作用。铁代谢的后天性和先天性缺陷是最常见的内科疾病之一。斑马鱼Frascati基因的突变导致严重的低色素性贫血和前红细胞阶段的发育停滞。使用定位克隆策略，我们发现Frascati编码线粒体溶质载体家族的一个成员。Frascati基因(mitoferrin，slc25a37)在斑马鱼和小鼠的胎儿和成体造血组织中高表达。我们假设Frascati负责将铁输送到线粒体，特别是发育中的红系细胞的线粒体。这个应用程序的目标是检验这一假设。我们建议通过以下两个特定目标来实现这一目标：特定目标1：分析Frascati基因的生化功能。1.1将利用永生化细胞和缺乏frascati活性的斑马鱼胚胎来研究frascati基因在线粒体铁获取中的作用。1.2通过在大肠杆菌中以包涵体形式表达重组蛋白及其在蛋白脂质体中的重组，研究Frascati线粒体转运体的生理底物和运输特性。具体目标2：分析哺乳动物中的frascati基因。2.1将通过靶向基因破坏来研究Frascati基因在小鼠中的功能。了解frascati基因的功能将直接关系到我们对缺铁、贫血和铁超载等人类疾病的理解。

DESCRIPTION (provided by applicant): The objective of this proposal is to understand the role of frascati, a novel mitochondrial solute transporter (SLC25), in vertebrate erythropoiesis and iron metabolism. Acquired and congential defects in iron metabolism from either deficiency or excess are one of the most common medical diseases. Mutations in the zebrafish frascati gene lead to a profound hypochromic anemia and a developmental arrest at the pro- erythroblast stage. Using a positional cloning strategy, we showed that frascati encodes a member of the mitochondrial solute carrier family. The frascati gene (mitoferrin, slc25a37) is highly expressed in fetal and adult hematopoietic tissues of zebrafish and mouse. We hypothesize that frascati is responsible for delivering iron to the mitochondria, and in particular, the mitochondria of developing erythroid cells. The goal of this application is to test this hypothesis. We propose to accomplish this goal by the following two specific aims: Specific Aim 1: Analysis of the biochemical function of the frascati gene. 1.1 The role of the frascati gene in mitochondrial iron acquisition will be studied using immortalized cells and zebrafish embryos deficient in frascati activity. 1.2 The physiologic substrate and transport properties of the frascati mitochondrial transporter will be studied by expression of recombinant protein as inclusion bodies in E. coli and their reconstitution in proteoliposomes. Specific Aim 2: Analysis of the frascati gene in mammalian organisms. 2.1 The function of the frascati gene in mouse will be studied by targeted gene disruption. Insight into the function of the frascati gene will be directly relevant to our understanding of human disorders of iron deficiency anemia and iron-overload.