Regulation of heme synthesis by mitochondrial proteins

线粒体蛋白对血红素合成的调节

• 批准号: 10664950
• 负责人: Yvette Y Yien
• 金额: $ 39.75万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10664950
• 关键词: Cell membrane; Cells; Child; Communities; Data Set; Disease; Enzymes; Erythroid; Erythroid Cells; Exclusion; Genetic; Goals; Heme; Homeostasis; Housekeeping; Iron; Iron Metabolism Disorders; Knowledge; Life; Metabolism; Mitochondria; Mitochondrial Proteins; Oxidation-Reduction; Pathway interactions; Patients; Play; Porphyrias; Porphyrins; Process; Proteins; Proteomics; Reaction; Regulation; Research; Respiration; Role; Tissues; Underserved Population; Woman; cell type; cytotoxic; genome sequencing; health management; interest; iron metabolism; mutant; novel; programs; protein complex; success; transcriptome sequencing; unfoldase; whole genome

ABSTRACT The long-term goal of this project is to identify the mechanisms that regulate “housekeeping” mitochondrial heme metabolism. Heme plays a central role in the redox reactions of life-essential processes such as mitochondrial respiration. My research program is particularly interested in 1. identifying proteins that regulate mitochondrial heme/porphyrin transport and 2. proteins that are part of the housekeeping mitochondrial homeostasis machinery that structurally or functionally interact with the core enzymes of the heme synthesis pathway. While the enzymes of the heme synthesis are well characterized and identical in all tissues, the regulatory mechanisms that couple heme synthesis to cellular requirements are very poorly understood. The importance of these regulatory mechanisms is underscored by the existence of disorders of heme synthesis and iron metabolism that are caused by dysregulation of proteins that are commonly associated with “housekeeping” homeostatic processes or mitochondrial respiration. Although all tissues require heme, most of our studies on regulatory aspects of heme synthesis have focused on erythroid cells to the exclusion of understanding heme synthesis in other cell types. This project uses our knowledge of erythroid heme synthesis as a springboard to identify heme regulatory mechanisms that are required for housekeeping heme synthesis. Project 1 aims to identify proteins that are required for mitochondrial porphyrin transport in non-erythroid cells. Heme intermediates are photosensitive and cytotoxic, requiring mechanisms for cells to quickly and efficiently transport heme intermediates across cell membranes, to the next enzyme in the heme synthetic pathway. When efficient transport does not occur, cytotoxic porphyrins accumulate in cells, potentially causing porphyria and heme deficiency. While TMEM14C is essential for porphyrin transport in erythroid cells, TMEM14 proteins are not required for heme synthesis in non-erythroid cells. Using a combination of proteomics and whole genome sequencing/RNAseq analysis of TMEM14C suppressor mutants, we will identify novel mitochondrial proteins that regulate porphyrin transport in non-erythroid cells. The long-term goal of Project 2 is to understand the regulation of the heme synthesis complex by proteins that regulate housekeeping mitochondrial homeostasis. During this project period, we focus on the ubiquitous mitochondrial unfoldase, CLPX, which plays an essential role in regulating the activity and protein stability of heme synthesis enzymes. We show that the function of CLPX is highly tissue-specific, and propose to understand its role in the systemic regulation of heme metabolism in the setting of “housekeeping” heme synthesis. These studies will provide essential datasets that will be invaluable to the mitochondrial protein unfoldase community, but will also be essential for determining how CLPX globally regulates mitochondrial homeostasis via tight regulation of heme.

抽象的 该项目的长期目标是确定调节“家政”线粒体的机制 血红素代谢。血红素在生命为生过程的氧化还原反应中起着核心作用，例如 线粒体呼吸。我的研究计划对1特别感兴趣。确定蛋白质 调节线粒体血红素/卟啉转运和2。蛋白质是管家的一部分 线粒体稳态机械在结构或功能上与核心酶相互作用 血红素合成途径。血红素合成的酶在所有方面都具有很好的特征和相同 组织，将血红素合成与细胞需求的调节机制非常差 理解。这些监管机制的重要性是由 血红素合成和铁代谢是由通常相关的蛋白质失调引起的 带有“家政”稳态过程或线粒体呼吸。尽管所有组织都需要血红素，但 我们关于血红素合成调节方面的大多数研究都集中在红细胞细胞上，以排除 了解其他细胞类型中的血红素合成。该项目使用我们对红血管合成的知识 作为识别管家血红素合成所需的血红素调节机制的跳板。 项目1旨在识别非果蝇中线粒体卟啉所需的蛋白质 细胞。血红素中间体具有光敏和细胞毒性，需要细胞快速和 有效地将血红素中间体跨细胞膜运输到血红素合成中的下一个酶 路径。当不进行有效的转运时，细胞毒性卟啉会积聚在细胞中，可能导致 卟啉症和血红素缺乏症。虽然TMEM14C对于红细胞细胞中的卟啉转运至关重要，但 非果蝇细胞中血红素合成不需要TMEM14蛋白。结合 蛋白质组学和TMEM14C抑制突变体的全基因组测序/RNASEQ分析，我们将识别 新的线粒体蛋白质，可调节非果蝇细胞中的卟啉转运。长期目标 项目2是为了了解调节管家的蛋白质对血红素合成复合物的调节 线粒体稳态。在这个项目期间，我们专注于无处不在的线粒体展进来， CLPX在调节血红素合成酶的活性和蛋白质稳定性中起着至关重要的作用。 我们表明，CLPX的功能是高度组织特异性的，并且建议了解其在系统性中的作用 在“管家”血红素合成的环境中调节血红素代谢。这些研究将提供 对于线粒体蛋白展开群社区来说，这将是无价的，但也将是 确定CLPX如何通过血红素的严格调节来调节线粒体稳态至关重要。