Structural Insights into the Function of Frataxin

Frataxin 功能的结构见解

• 批准号: 7856159
• 负责人: TIMOTHY Louis STEMMLER
• 金额: $ 3.27万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-16 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7856159
• 关键词: Affect; Anabolism; Binding; Biochemical; Complex; Copper; Country; Coupling; Data; Disease; Elements; Environment; Event; Friedreich Ataxia; Goals; Heme; Homeostasis; Human; In Vitro; Iron; Laboratories; Lead; Metals; Mitochondria; Mitochondrial Proteins; Molecular; Molecular Chaperones; NMR Spectroscopy; Neurodegenerative Disorders; Oxygen; Pathway interactions; Patients; Physiological; Play; Positioning Attribute; Production; Protein Binding; Proteins; Publishing; Regulation; Reporting; Role; Solutions; Structure; Testing; Work; Yeasts; base; cofactor; ferrochelatase; frataxin; heme biosynthesis; in vivo; innovation; insight; mutant; oxidation; protein complex; treatment strategy; yeast protein

DESCRIPTION (provided by applicant): Frataxin, a mitochondrial protein known to participate in regulating cellular iron homeostasis, has recently been suggested to act as a mitochondrial iron chaperone for heme and Fe-S cluster biosynthesis. A reduced level of frataxin is the principal cause of the autosomal recessive neurodegenerative disorder Friedreich's ataxia (FRDA), which affects 1 in 50,000 humans. Frataxin has been shown to interact with the proteins that catalyze heme 2Fe-2S cluster production, suggesting frataxin plays a direct role in Fe-cofactor production. The interaction between yeast frataxin (Yfh1p) and the proteins Hem15p and Isu1p are believed to promote iron delivery and the cellular synthesis of heme and 2Fe-2S clusters, respectively, however almost nothing is known about how these proteins interact and how iron is delivered and transferred during complex formation. The objective of this application is to characterize frataxins role in both the heme and Fe-S cluster biosynthetic pathways. Our central hypothesis is that monomeric frataxins binds ferrous iron, protects the bound Fe(II) against oxidation in the potentially oxygen rich environment of the mitochondrion and then delivers reduced metal to target proteins involved in both the heme and Fe-S assembly pathways. This hypothesis is based on our laboratories biochemical and structural characterization of monomeric Yfh1p, as well as published reports of frataxins in vitro iron delivery activity. The rationale for our proposed studies is if we can distinguish frataxins role in regulating cellular iron homeostasis, we can help elucidate what pathways are deficient in FRDA patients, and we expect this information will lead to more successful treatment strategies for the disorder. We are in an excellent position to complete this work as we have recently cloned, expressed and solved the solution structure of yeast frataxin, and our laboratory has begun to characterize how Yfh1p binds iron and interacts with its protein binding partners. In addition, we have begun to test the physological significance of our findings both in vitro and in vivo.

描述(申请人提供)：Frataxin是一种线粒体蛋白，参与调节细胞铁稳态，最近被认为是血红素和铁-S簇生物合成的线粒体铁伴侣。Frataxin水平降低是常染色体隐性遗传性神经退行性疾病Friedreich‘s共济失调(FRDA)的主要原因，每50,000人中就有1人受到影响。Frataxin已被证明与催化血红素2Fe-2S簇产生的蛋白质相互作用，这表明Frataxin在铁辅助因子的产生中起着直接作用。酵母Frataxin(Yfh1p)与蛋白质hem15p和Isu1p之间的相互作用被认为分别促进了铁的输送和血红素和2Fe-2S簇的细胞合成，然而，几乎不知道这些蛋白质如何相互作用以及铁在复合体形成过程中是如何输送和转移的。这项应用的目的是表征Frataxins在血红素和Fe-S簇生物合成途径中的作用。我们的中央 假说是，单体Frataxins与亚铁结合，保护结合的Fe(II)在线粒体潜在的富氧环境中免受氧化，然后将还原的金属输送到参与血红素和Fe-S组装途径的靶蛋白。这一假说是基于我们实验室对单体Yfh1p的生化和结构表征，以及已发表的Frataxin体外铁传递活性的报告。我们提出研究的基本原理是，如果我们能够区分Frataxins在调节细胞铁稳态中的作用，我们就可以帮助阐明FRDA患者缺乏哪些途径，我们预计这些信息将导致对这种疾病的更成功的治疗策略。我们处于非常有利的地位来完成这项工作，因为我们最近已经克隆、表达和解决了 酵母Frataxin的溶液结构，我们的实验室已经开始表征Yfh1p如何与铁结合以及如何与其蛋白质结合伙伴相互作用。此外，我们已经开始在体外和体内测试我们的发现的生理学意义。