Regulation Of Metabolism And Gene Expression By Iron-Sulfur Clusters - Resubmission - 1

铁硫簇对代谢和基因表达的调节 - 重新提交 - 1

• 批准号: 10534796
• 负责人: Richard Lewis Possemato
• 金额: $ 6.41万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10534796
• 关键词: Alleles; Anabolism; Ataxia; Binding; Biological Assay; Cell Death; Cell Line; Cell model; Cells; Complex; Cysteine; Data; Defect; Disease; Elements; Exhibits; Foundations; Functional disorder; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Epistasis; Genetic Translation; Goals; Grant; Heritability; Human; Human Pathology; Individual; Iron; Iron Metabolism Disorders; Iron Overload; Knock-out; Knockout Mice; Knowledge; Link; Lung Neoplasms; Malignant Neoplasms; Mediating; Messenger RNA; Metabolism; Methods; Molecular; Molecular Conformation; Mutagenesis; Mutation; Nutrient; Outcome; Outcome Study; Oxidative Stress; Oxygen; Pathology; Pathway interactions; Phenotype; Proteins; RNA; RNA Interference; Regulation; Reporter; Research; Starvation; Stimulus; Sulfur; Syndrome; Testing; Tissues; Transcript; Translational Regulation; Translations; Ubiquitin; base; biophysical techniques; cancer cell; cancer therapy; cofactor; crosslink; crosslinking and immunoprecipitation sequencing; experimental study; human disease; innovation; iron metabolism; mouse model; novel; novel strategies; protein activation; response; sensor; ubiquitin ligase

Iron-sulfur clusters (ISCs) are essential protein cofactors whose dysregulation is linked to a wide range of debilitating diseases including Friedrch’s ataxia. This pathology is due in part to the use of ISCs in iron-responsive proteins (IRPs), which control the translation of mRNAs in the iron-starvation response. We recently found that by suppressing ISC biosynthesis we can robustly activate this IRP-mediated iron-starvation response, sensitizing cancer cells to cell death by ferroptosis. Our preliminary data, which form the premise of our application, point to an unexpected mode of IRP2 regulation by ISCs and demonstrate that the mechanism by which ISCs modulate the iron-starvation response, and therefore impact human disease, remains unclear. Our long-term goal is to dissect the mechanisms by which ISCs regulates cellular responses to changing iron and oxygen availability and how this response is mediated by IRPs. We anticipate that these discoveries will lead to the identification of pathologies for diseases where prior ISC involvement was unclear, to new treatments for diseases of ISC dysregulation, and will facilitate novel methods to sensitize cancer cells to ferroptosis. The objective of this grant is to dissect how ISCs control IRP2 activation and to comprehensively define the targets of IRP1 and IRP2 and the conditions under which they are activated. Our overarching hypothesis is that ISCs integrate iron and oxygen level inputs to effect specific translational responses via differential regulation of IRPs. Our rationale is that identification of the specific mechanisms by which IRPs are activated and the targets that they activate will enable the discovery of novel strategies to treat cancer and disorders of ISC metabolism. Our specific aims will test the following hypotheses: (Aim 1) ISCs can activate the iron-starvation response through an IRP2-mediated mechanism; (Aim 2) IRPs exhibit differential IRE binding in response to iron and oxygen level modulation. Upon completion of these aims we will (1) gain an understanding of how cells sense iron and oxygen levels and integrate these inputs using ISC sensors and (2) identify IRP regulated target genes and the conditions in which they are regulated. This contribution is significant because dysregulation of IRPs occurs frequently in human pathologies and inducing activation of the iron starvation response sensitizes cancer cells to ferroptotic cell death. This research is innovative because we challenge paradigms in cellular iron-sensing to arrive at a comprehensive mechanism by which cells respond to changes in the level of this important nutrient, and because we utilize heretofore unique approaches to identify RNAs regulated by the iron starvation response and define their activation by upstream stimuli. The outcomes of this study promise disrupt our understanding of iron sensing and have broad implications for the treatment of cancer as well as human diseases related to defects in iron metabolism and storage.

铁硫簇（ISCs）是必需的蛋白质辅助因子，其失调与包括Friedrch共济失调在内的多种衰弱性疾病有关。这种病理部分是由于ISCs在铁反应蛋白（IRPs）中的使用，IRPs控制铁饥饿反应中mrna的翻译。我们最近发现，通过抑制ISC的生物合成，我们可以强有力地激活irp介导的铁饥饿反应，使癌细胞对铁凋亡的细胞死亡敏感。我们的初步数据构成了我们应用的前提，指出了ISCs调控IRP2的一种意想不到的模式，并表明ISCs调节铁饥饿反应并因此影响人类疾病的机制尚不清楚。我们的长期目标是剖析ISCs调节细胞对改变铁和氧可用性的反应的机制，以及IRPs如何介导这种反应。我们预计这些发现将导致先前不清楚ISC参与的疾病的病理鉴定，ISC失调疾病的新治疗方法，并将促进新方法使癌细胞对铁凋亡敏感。这项资助的目的是剖析ISCs如何控制IRP2的激活，并全面定义IRP1和IRP2的靶点以及它们被激活的条件。我们的总体假设是ISCs整合铁和氧水平输入，通过IRPs的差异调节来影响特定的翻译反应。我们的基本原理是，确定IRPs被激活的特定机制及其激活的靶标将有助于发现治疗癌症和ISC代谢紊乱的新策略。我们的具体目标将检验以下假设：（目标1）ISCs可以通过irp2介导的机制激活铁饥饿反应；（目的2）IRPs在铁和氧水平调节下表现出不同的IRE结合。在完成这些目标后，我们将(1)了解细胞如何感知铁和氧水平，并使用ISC传感器整合这些输入；(2)识别IRP调节的靶基因及其调节条件。这一贡献是重要的，因为IRPs的失调在人类病理中经常发生，诱导铁饥饿反应的激活使癌细胞对铁嗜性细胞死亡敏感。这项研究具有创新意义，因为我们挑战了细胞铁传感的范式，从而得出细胞对这种重要营养物质水平变化作出反应的综合机制，并且因为我们利用迄今为止独特的方法来识别受铁饥饿反应调节的rna，并定义它们在上游刺激下的激活。这项研究的结果有望打破我们对铁感知的理解，并对癌症以及与铁代谢和储存缺陷相关的人类疾病的治疗具有广泛的意义。