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.

项目摘要/摘要 PI要求支持其在生物学方面的铁运输和调节研究计划 系统。使用强大的生物物理，生物分析和数学工具，Pi及其 同事建议在孤立的细胞器中表征和量化主要铁物种， 来自多种生物系统的全细胞和器官。 Mössbauer光谱法会 成为主要的生物物理工具，具有EPR和UV-VIS光谱镜扮演支持角色。 萌芽酵母和人类细胞的各种遗传菌株将富集在57FE中。线粒体， 细胞质，液泡和其他细胞器将分离出来。这些细胞中的主要铁物种 组件将进行探测。基于普通差异方程式的数学模型将是 开发以分析获得的结果并生成系统的级别描述 贩运和监管。全世界没有其他小组以这种方式调查FE。酵母菌菌株 正在研究MRS3/4，位于线粒体上的高亲和力Fe进口商 内膜已被删除和过表达。其他与Fe相关的酵母菌菌株 以及人类的Jurkat细胞，其中有丝曲链蛋白（MRS3/4的同源物）和铁蛋白被敲除 下降，也将进行调查。大肠杆菌和其他原核生物的Fe含量将是 类似地探索。中央生物分析工具将是位于液相色谱系统 在与在线电感耦合等离子体相关的冷藏厌氧手套箱中 质谱仪和在线电喷雾电离质谱仪。这个LC- （ICP）-ESI-MS系统将在全球范围内成为独特的。它将用于表征数十个不稳定的 PI和他的小组发现的低分子质量（LMM）金属络合 细胞器，细胞质，血浆和大肠杆菌。线粒体中的LMM FE复合物 大约580 DA（称为FE580）正在积极调查。 FE580很可能被用作 铁硫簇（ISC）组件的原料和血红素的铁插入步骤 生物合成。称为X-S的含LMM硫的物种的组成也将是 调查。 X-S与ISC组合相关的线粒体导出，可能是 用于组装胞质ISC并调节运输。血液中的lmm fe物种 血浆称为“非转移蛋白结合铁”或NTBI的等离子体将使用猪进行研究 进食管和采样导管已通过手术植入。 NTBI损坏器官 FE超负荷疾病（例如血色素沉着病）的患者。各种小鼠菌株 将研究相关疾病，以确定累积的FE形式 器官。还将检查缺氧对FE积累的影响。