Systematic Genome-Wide Characterization of Iron Homeostasis

铁稳态的系统全基因组表征

• 批准号: 8980525
• 负责人: Marco Jost
• 金额: $ 5.07万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8980525
• 关键词: Address; Affect; Anemia; Antibiotic Therapy; Antibiotics; Bacillus anthracis; Bacterial Infections; Base Sequence; Biochemical; Biochemical Genetics; Biological Models; Brain; Buffers; Cell Death; Cell physiology; Cells; Clustered Regularly Interspaced Short Palindromic Repeats; Combined Antibiotics; Complement; Complex; Data; Data Set; Disease; Employee Strikes; Enzymes; Equilibrium; Escherichia; Escherichia coli; Essential Genes; Eukaryota; Future; Gene Expression; Genes; Genetic Screening; Genetic study; Gram-Negative Bacteria; Growth; Health; Heme; Hemochromatosis; Homeostasis; Human; Infection; Invaded; Iron; Iron Overload; Link; Liver diseases; Malnutrition; Mammalian Cell; Mammals; Maps; Measurement; Mediating; Messenger RNA; Metabolic; Metabolic Pathway; Metabolism; Metals; Micronutrients; Mitochondria; Molecular Chaperones; Neurodegenerative Disorders; Nutrient; Organism; Oxidative Stress; Oxygen; Pathway interactions; Phenotype; Physiological; Physiology; Prokaryotic Cells; Proteins; Reactive Oxygen Species; Repression; Research Personnel; Resources; Ribosomes; Role; Small RNA; Source; Staphylococcus aureus; Structure; System; Testing; Time; base; career; cofactor; cognitive development; cost; deep sequencing; deletion library; deprivation; genome-wide; genome-wide analysis; insight; interest; iron deficiency; member; metabolomics; microbial community; pathogen; public health relevance; research study; response; small molecule; trafficking; uptake

 DESCRIPTION (provided by applicant): As a cofactor for thousands of enzymes, iron is an essential micronutrient. Yet, free iron is toxic because it catalyzes rapid formation of damaging reactive oxygen species. Therefore, homeostasis systems exert tight control on iron levels in all organisms and gene expression is adjusted in response to iron deprivation and iron abundance: expression of at least 100 genes is known to be iron-dependent in Escherichia coli. In humans, disruption of iron homeostasis contributes to severe diseases: iron accumulation in the brain is linked to neurodegenerative diseases, iron overload causes the liver disease hemochromatosis, and iron deficiency leads to anemia and impaired cognitive development. Furthermore, invading bacterial pathogens hijack iron out of human proteins to establish infections. These considerations underscore the essential role of iron homeostasis to human health. Because of a lack of studies examining the total cellular framework for the response to both iron deficiency and iron overload, however, how iron homeostasis is integrated into cell physiology is still unclear. Here, to address this deficiency, a two-pronged genome-wide approach is used consisting of: (1) ribosome profiling to determine how expression of genes changes over time in response to varying iron levels; and (2) genome-wide screens to identify genes that are important for survival under iron overload and iron deficiency. This approach is complemented by biochemical and genetic studies to mechanistically characterize new players in iron homeostasis. Importantly, two model systems will be investigated, the gram-negative bacterium Escherichia coli and human cells, allowing for an informative comparison of the two systems that will be essential to develop antibiotics specifically targeted at bacterial iron homeostasis. This comprehensive study will provide a time-resolved and holistic view of the response to iron and identify new players in iron homeostasis, including post-transcriptional regulators, transport systems to take up iron from different sources, and metabolic pathways that become activated in response to iron. Insight obtained from these experiments will benefit understanding of iron homeostasis diseases and treatment of bacterial infections.

 描述（由适用提供）：作为数千种酶的辅助因子，铁是必不可少的微量营养素。然而，游离铁是有毒的，因为它会催化有害的活性氧的快速形成。因此，体内平衡系统对所有生物的铁水平施加严格的控制，并根据铁的剥夺和铁的丰度来调整基因表达：已知至少100个基因的表达在大肠杆菌中是铁依赖性的。在人类中，铁稳态的破坏会导致严重疾病：大脑中的铁积累与神经退行性疾病有关，铁超负荷会导致肝病血糖症，而铁缺乏会导致贫血和认知发展受损。此外，入侵细菌病原体从人蛋白中劫持了铁，以建立感染。这些考虑因素降低了铁稳态对人类健康的重要作用。但是，由于缺乏研究，研究了对铁缺乏症和铁超负荷反应的总细胞框架，因此如何将铁稳态整合到细胞生理学中尚不清楚。在这里，为了解决这一缺陷，使用了两种基因组的两种基因组方法，包括：（1）核糖体分析以确定基因表达如何随时间而变化，以响应不同的铁水平； （2）全基因组筛选以识别铁超载和铁缺乏症在生存中很重要的基因。这种方法是通过生化和遗传研究完成的，可以机械地表征铁稳态中的新参与者。重要的是，将研究两个模型系统，即革兰氏阴性细菌大肠杆菌和人类细胞，从而可以对这两个系统进行信息比较，这对于开发针对细菌铁稳态的抗生素至关重要。这项全面的研究将提供对铁的反应的时间和整体观点，并确定铁稳态中的新参与者，包括转录后调节器，运输系统，从不同来源占据铁，以及因铁而被激活的代谢途径。从这些实验获得的洞察力将使对铁稳态疾病的了解和细菌感染的治疗。