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（由申请人提供）：作为数千种酶的辅助因子，铁是一种必需的微量营养素，然而，游离铁是有毒的，因为它会催化有害活性氧的快速形成，因此，体内平衡系统对所有体内的铁水平进行严格控制。生物体和基因表达会根据铁缺乏和铁丰度进行调整：已知大肠杆菌中至少有 100 个基因的表达是铁依赖性的。在人类中，铁稳态被破坏。导致严重疾病：大脑中铁的积累与神经退行性疾病有关，铁超载会导致肝脏疾病血色素沉着症，缺铁会导致贫血和认知发育受损。此外，入侵的细菌病原体会劫持人类蛋白质中的铁以造成感染。这些考虑强调了铁稳态对人类健康的重要作用，然而，由于缺乏对铁缺乏和铁过载反应的总细胞框架的研究，铁稳态如何融入细胞生理学尚不清楚。目前尚不清楚，为了解决这一缺陷，采用了双管齐下的全基因组方法，包括：（1）核糖体分析以确定基因表达如何随时间变化以响应不同的铁水平；广泛的筛选来识别对铁过载和铁缺乏下的生存很重要的基因。这种方法辅以生化和遗传学研究，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，即革兰氏阴性系统。大肠杆菌和人类细胞，可以对这两个系统进行信息比较，这对于开发专门针对细菌铁稳态的抗生素至关重要。这项综合研究将提供对铁反应的时间分辨和整体视图，并确定新的参与者。从这些实验中获得的见解将有助于理解铁稳态疾病和治疗，包括转录后调节因子、从不同来源吸收铁的运输系统以及响应铁而激活的代谢途径。细菌感染。