Deciphering a Novel Mechanism for Iron-sensing at Mitochondria and Its Role in Erythropoiesis

破译线粒体铁感应的新机制及其在红细胞生成中的作用

• 批准号: 10560352
• 负责人: Shiori Sekine
• 金额: $ 53万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10560352
• 关键词: Address; Anemia; Binding; Binding Proteins; Biological; Cell Death; Cell Line; Cell model; Cell physiology; Cells; Cessation of life; Characteristics; Communication; Cytosol; Data; Death Domain; Defect; Disease; Enhancers; Equilibrium; Erythrocytes; Erythroid; Erythroid Cells; Erythropoiesis; Exhibits; Globin; Goals; Heme; Hemoglobin; Hemoglobinopathies; Homeostasis; Human; In Vitro; Inherited; Iron; Iron Regulatory Protein 1; Iron deficiency anemia; Knockout Mice; Life; Lung; Mammals; Mass Spectrum Analysis; Mediating; Messenger RNA; Mitochondria; Mitochondrial Matrix; Mitochondrial Proteins; Modeling; Molecular; Molecular Biology Techniques; Monitor; Mus; Organelles; Organism; Outer Mitochondrial Membrane; Oxygen; Pathway interactions; Peptide Hydrolases; Phenocopy; Phenotype; Phosphotransferases; Play; Porphyrins; Protein Import; Proteins; Proteomics; Regulation; Reporting; Research Proposals; Role; Signal Transduction; Signaling Molecule; Stress; Sulfur; System; Testing; Transcriptional Activation; Transition Elements; Translations; Work; attenuation; biological adaptation to stress; cofactor; erythroid differentiation; erythroleukemic cell; heme 1; heme a; in vivo; inhibitor; insight; iron deficiency; iron metabolism; novel; novel therapeutic intervention; progenitor; proteostasis; response; success; therapeutic target; transcription factor

Abstract Iron is essential for eukaryotic life acting as a biological catalytic center of various proteins involved in diverse cellular processes. In human, the greatest portion of total body iron can be found as heme (an iron-containing porphyrin), the majority of which is in red blood cells in the form of hemoglobin that carries oxygen from the lung to the whole body. An imbalanced supply of iron, heme, or globin proteins leads to the shortage of functional hemoglobin, resulting in various types of anemia. Insufficient iron supply is particularly critical, as it causes so-called iron deficiency anemia, the most common form of anemia worldwide. Understanding the regulation of hemoglobin synthesis in erythroid cells is important for developing novel therapeutic strategies to treat red blood cell disorders. However, the molecular mechanisms underlying this regulation have not been fully understood. This research proposal aims to uncover these mechanisms by delineating iron-dependent regulation of the mitochondrial protein DELE1. It has been recently shown that in response mitochondrial stress, DELE1 acts as an activator of the stress responsive kinase HRI, a well-established regulator of globin translation in the erythroid lineage. Preliminary results in this proposal indicate that DELE1 activates HRI in iron-depleted cells by a novel mechanism distinct from previously reported mechanisms. These results also suggest the mitochondrial import of DELE1 and its subsequent protein stability is strictly regulated by intracellular iron availability. Thus, this proposal will test the hypothesis that iron-dependent mitochondrial proteostasis and import regulation of DELE1 are the core components of a novel mitochondrial iron-sensing pathway regulating the HRI-mediated stress response. The mechanisms how mitochondrial DELE1 activates cytosolic HRI in iron deficient conditions will be investigated using multiple advanced molecular biology techniques, in combination with mass spectrometry-based proteomics. The involvement of the DELE1-HRI pathway in terminal erythroid differentiation will be addressed using a murine erythroleukemia (MEL) cell line, an established erythroid cellular model, as well as a recently generated DELE1 deficient mouse. The success of the proposed work will provide novel molecular insights into mitochondrial iron-sensing and reveal the critical molecular players that are responsible for the communication between mitochondria and the cytosol in order to maintain cellular homeostasis under iron-deficient conditions.

抽象的 铁对于多种多样的各种蛋白质的生物催化中心至关重要 细胞过程。在人类中，可以找到全身铁的最大部分作为血红素（一种含铁 卟啉），其中大多数是在红细胞中以血红蛋白的形式出现的，该血红蛋白从 肺向全身。铁，血红素或球蛋白蛋白的不平衡供应导致短缺 功能性血红蛋白，导致各种类型的贫血。铁供应不足特别关键，因为 导致所谓的铁缺乏贫血，这是全世界最常见的贫血形式。了解 调节红细胞细胞中血红蛋白合成对于开发新的治疗策略至关重要 治疗红细胞疾病。但是，该调节的分子机制尚未 完全理解。该研究建议旨在通过描述铁依赖性来揭示这些机制 线粒体蛋白DELE1的调节。最近已经表明，在响应线粒体中 压力，DELE1充当压力响应激酶HRI的激活剂，GOLLI的良好调节剂 红细胞谱系中的翻译。该提案的初步结果表明，DELE1激活HRI 通过与先前报道的机制不同的新机制进行了耗尽铁的细胞。这些结果也是如此 建议DELE1的线粒体导入及其随后的蛋白质稳定性严格受到 细胞内铁的可用性。因此，该提案将检验以下假设：铁依赖性线粒体 DELE1的蛋白质和进口调节是新型线粒体铁感应的核心组成部分 调节HRI介导的应力反应的途径。线粒体DEE1激活的机制 将使用多个晚期分子生物学研究胞质HRI在铁不足条件下 技术与质谱基蛋白质组学结合使用。 DELE1-HRI的参与 末端红细胞分化的途径将使用鼠红血球血症（MEL）细胞来解决 线，已建立的红细胞细胞模型以及最近生成的DELE1缺陷小鼠。这 拟议的工作的成功将为线粒体铁感应和 揭示负责线粒体和线粒体之间交流的关键分子参与者 为了在铁缺陷型条件下维持细胞稳态以维持细胞稳态。