Iron Trafficking and Regulation in Biological Systems

生物系统中的铁贩运和调节

• 批准号: 10393033
• 负责人: PAUL A. LINDAHL
• 金额: $ 34.66万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10393033
• 关键词: Affinity; Anaerobic Bacteria; Biodiversity; Biophysics; Blood; Catheters; Cells; Complex; Coupled; Cytosol; Differential Equation; Disease; Electrospray Ionization; Enteral Feeding; Escherichia coli; Family suidae; Ferritin; Health; Hemochromatosis; Human; Hypoxia; Implant; Inner mitochondrial membrane; Investigation; Iron; Iron Overload; Jurkat Cells; Link; Liquid Chromatography; Mathematics; Metals; Mitochondria; Mossbauer Spectroscopy; Mouse Strains; Operative Surgical Procedures; Organ; Organelles; Patients; Plasma; Play; Prokaryotic Cells; Regulation; Research Support; Role; Saccharomycetales; Sampling; Spectrum Analysis; Sulfur; System; Vacuole; Yeasts; base; biological systems; biophysical tools; cell injury; genetic strain; heme biosynthesis; knock-down; mass spectrometer; mathematical model; metal complex; molecular mass; overexpression; programs; tool; trafficking

Project Summary/Abstract The PI requests support of his research program in Iron Trafficking and Regulation in Biological Systems. Using powerful biophysical, bioanalytical, and mathematical tools, the PI and his coworkers propose to characterize and quantify the major iron species in isolated organelles, whole cells and organs from a wide diversity of biological systems. Mössbauer spectroscopy will be the primary biophysical tool, with EPR and UV-vis spectroscopies playing supporting roles. Various genetic strains of budding yeast and human cells will be enriched in 57Fe. Mitochondria, cytosol, vacuoles and other organelles will be isolated. The major Fe species in these cellular components will be probed. Ordinary-differential-equations-based mathematical models will be developed to analyze the results obtained and to generate a system’s level description of Fe trafficking and regulation. No other group worldwide investigates Fe in this way. Yeast strains are being investigated in which Mrs3/4, high-affinity Fe importers located on the mitochondrial inner membrane, have been deleted and overexpressed. Other Fe-associated yeast strains, as well as human Jurkat cells in which mitoferrins (homologs of Mrs3/4) and ferritin are knocked- down, will also be investigated. The Fe content of Escherichia coli and other prokaryotes will be similarly explored. The central bioanalytical tool will be a liquid chromatography system located in a refrigerated anaerobic glove box that is linked to an on-line inductively coupled plasma mass spectrometer AND to an on-line electrospray ionization mass spectrometer. This LC- (ICP)-ESI-MS system will be unique worldwide. It will be used to characterize dozens of labile low-molecular-mass (LMM) metal complexes that the PI and his group have discovered in organelles, cytosol, blood plasma, and in E. coli. A LMM Fe complex in mitochondria that has a mass of ca. 580 Da (called Fe580) is actively under investigation. Fe580 is most probably used as feedstock for iron-sulfur cluster (ISC) assembly and for the iron-insertion step of heme biosynthesis. The composition of a LMM sulfur-containing species called X-S will also be investigated. X-S is exported from mitochondria in association with ISC assembly, and it may be used to assemble cytosolic ISCs and to regulate Fe trafficking. A LMM Fe species in blood plasma called “non-transferrin-bound iron” or NTBI will be investigated using pigs into which a feeding tube and sampling catheters have been surgically implanted. NTBI damages organs in patients with Fe-overload diseases such as hemochromatosis. Various strains of mice with Fe- associated diseases will be investigated to determine the form of Fe that accumulates in their organs. The effect of hypoxia on Fe accumulation will also be examined.

项目概要/摘要 PI请求支持他的铁贩运和生物监管研究项目 PI 和他的系统使用强大的生物物理、生物分析和数学工具。 同事们建议对分离的细胞器中的主要铁物种进行表征和量化， 来自多种生物系统的完整细胞和器官。 是主要的生物物理工具，EPR 和紫外可见光谱发挥辅助作用。 芽殖酵母和人体细胞的各种遗传菌株将富集57Fe线粒体， 细胞质、液泡和其他细胞器将被分离出这些细胞中的主要铁形态。 将探讨基于常微分方程的数学模型。 开发用于分析获得的结果并生成 Fe 的系统级描述 全世界没有其他组织以这种方式研究铁。 正在研究Mrs3/4，位于线粒体上的高亲和力铁输入者 内膜，已被删除并过度表达其他 Fe 相关酵母菌株，如 以及人类 Jurkat 细胞，其中线粒体铁蛋白（Mrs3/4 的同源物）和铁蛋白被敲除 - 下来，还将研究大肠杆菌和其他原核生物的铁含量。 类似地，中央生物分析工具将是液相色谱系统。 在与在线电感耦合等离子体相连的冷藏厌氧手套箱中 质谱仪和在线电喷雾电离质谱仪。 (ICP)-ESI-MS 系统将在全球范围内独一无二，将用于表征数十种不稳定物质。 PI 和他的团队发现了低分子质量 (LMM) 金属配合物 细胞器、细胞质、血浆和大肠杆菌中的 LMM Fe 复合物，具有一个 质量约为 580 Da（称为 Fe580）的物质正在积极研究中。 铁硫簇 (ISC) 组装和血红素铁插入步骤的原料 称为 X-S 的 LMM 含硫物质的组成也将是 X-S 是从线粒体中输出的，与 ISC 组装有关，并且可能是这样。 用于组装细胞质 ISC 并调节血液中的 LMM Fe 物质运输。 称为“非转铁蛋白结合铁”或 NTBI 的血浆将使用猪进行研究，其中 饲管和取样导管已通过手术植入 NTBI 损伤器官。 患有铁超载疾病（例如血色素沉着病）的各种品系小鼠。 将调查相关疾病以确定在其体内积聚的铁的形式 还将检查缺氧对铁积累的影响。