Aberrant Cardiolipin Dynamics in Barth Syndrome - Renewal - 1

巴特综合征中的异常心磷脂动态 - 更新 - 1

• 批准号: 10321270
• 负责人: Michael Schlame
• 金额: $ 35.6万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 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 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10321270
• 关键词: 3-Methylglutaconic aciduria type 2; Acrosome; Acyltransferase; Address; Adenine Nucleotide Translocase; Affect; Automobile Driving; Biogenesis; Biological Process; Biology; Cardiolipins; Cardiomyopathies; Cell Differentiation process; Characteristics; Clinical; Complex; Coupling; Crista ampullaris; Crowding; Data; Defect; Dependence; Development; Disease; Dissection; Dissociation; Drosophila genus; Electrons; Energy Metabolism; Enzymes; Fatigue; Fatty Acids; Functional disorder; Funding; Germ; Germ Cells; Goals; Growth; Half-Life; Health; Homeostasis; Human; Impairment; In Vitro; Individual; Inner mitochondrial membrane; Knowledge; Label; Life; Link; Lipids; Membrane; Membrane Proteins; Metabolic Diseases; Microscopic; Mission; Mitochondria; Mitochondrial Diseases; Mitochondrial Membrane Protein; Molecular; Mus; Muscle; Muscle Mitochondria; Muscle Weakness; Mutation; Neutropenia; Organelles; Output; Oxidative Phosphorylation; Pathologic; Phase; Phospholipids; Protein Isoforms; Proteins; Proteomics; Public Health; Reaction; Research; Role; Spatial Distribution; Specificity; Spermatogenesis; Stress; Symptoms; System; Techniques; Testing; Testis; United States National Institutes of Health; Unsaturated Fatty Acids; Work; body system; density; disability; fly; in vivo; insight; lipid disorder; lipidome; membrane biogenesis; mitochondrial membrane; mitochondrial metabolism; mouse model; novel; physical state; respiratory; stable isotope; tomography

Project Summary/Abstract Mitochondria are membrane-rich organelles that are essential to eukaryotic life. Detailed insight has emerged into the assembly and the dynamics of mitochondrial membrane proteins, but a fundamental gap has remained in understanding mitochondrial lipids. Barth syndrome (BS) is a disorder of the mitochondrial lipid metabolism, in particular the metabolism of the mitochondria-specific phospholipid cardiolipin (CL), and thus provides a unique opportunity to address this gap in a context relevant to human health. BS is caused by mutations in tafazzin, an enzyme that catalyzes CL remodeling, i.e. the fatty acid exchange reaction by which the characteristic molecular composition of CL is created. The objective of this application is to identify mechanism and function of CL remodeling. This objective fits into our broad goals to understand the function of CL in mitochondria and to unravel the molecular pathophysiology of BS. We discovered that the global assembly of the system of oxidative phosphorylation (OXPHOS) is driving CL remodeling. We hypothesize that CL remodeling reduces the packing stress imposed on mitochondrial lipids by the extremely high protein concentration, which arises in mitochondrial membranes due to the OXPHOS system and other proteins. Thus, the function of CL remodeling is to stabilize lipid-protein interactions in order to allow the assembly of protein- crowded membranes. To test this hypothesis, we will focus on two features of BS, which are both dependent on the high concentration of membrane proteins. First, we will identify the cause of energy deficiency in BS. We will determine the effect of the complexes of OXPHOS on CL remodeling in flight muscle mitochondria and vice versa, the effect of CL remodeling on the OXPHOS system. We will then test whether disturbing either CL remodeling or the OXPHOS system has any effect on the half-life of individual components of mitochondrial membranes because our preliminary data suggest that CL remodeling is essential for CL stability. Second, we will determine the mechanism of the arrest of spermatogenesis in BS. Our preliminary data suggest that CL remodeling is essential for the formation of condensed mitochondria, a unique type of organelle that emerges during germ cell development and that accumulates a specific isoform of the ADP/ATP carrier (Ant4) at high concentration. Our data also suggest that condensed mitochondria are involved in the biogenesis of acrosomes. We will identify the role of CL remodeling in the formation of condensed mitochondria and then establish the mechanism by which condensed mitochondria support the biogenesis of acrosomes. Our application relies on cutting-edge techniques, such as lipidome-wide flux analysis with stable isotopes, cryo- electron microscopic tomography, and quantitative proteomics with isobaric labeling. The proposed study is significant because it will identify the mechanism and the function of CL remodeling, a widely conserved reaction of uncertain significance, and because it will establish the pathologic mechanism of BS.

项目摘要/摘要 线粒体是富含膜的细胞器，对真核生活至关重要。详细的见解已经出现 进入线粒体膜蛋白的组装和动力学，但基本间隙仍然存在 在理解线粒体脂质时。 Barth综合征（BS）是线粒体脂质代谢的一种疾病， 特别是线粒体特异性磷脂心磷脂（CL）的代谢，因此提供了一个 在与人类健康相关的情况下解决这一差距的独特机会。 BS是由突变引起的 tafazzin，一种催化Cl重塑的酶，即脂肪酸交换反应 创建了Cl的特征分子组成。此应用的目的是确定 CL重塑的机理和功能。这个目标符合我们的广泛目标，以了解 线粒体中的CL并阐明BS的分子病理生理。我们发现全球 氧化磷酸化系统（OXPHOS）的组装正在驱动CL重塑。我们假设 CL重塑减少了极高蛋白质施加的线粒体脂质的填料应力 浓度是由于OXPHOS系统和其他蛋白质引起的线粒体膜产生的。因此， CL重塑的功能是稳定脂质 - 蛋白质相互作用，以使蛋白质组装 拥挤的膜。为了检验这一假设，我们将重点介绍BS的两个特征，这两者都取决于 在高浓度的膜蛋白上。首先，我们将确定BS能源缺乏的原因。 我们将确定Oxphos络合物对飞行肌肉线粒体和 反之亦然，CL重塑对OXPHOS系统的影响。然后，我们将测试是否干扰任何一个CL 重塑或OXPHOS系统对线粒体各个组件的半衰期有任何影响 膜是因为我们的初步数据表明CL重塑对于CL稳定性至关重要。第二，我们 将确定BS中精子发生停滞的机制。我们的初步数据表明CL 重塑对于形成凝结线粒体是必不可少的，这是一种独特的细胞器类型 在生殖细胞发育过程中，积累了ADP/ATP载体（ANT4）的特定同工型 专注。我们的数据还表明，凝结的线粒体参与 ACROSOMES。我们将确定CL重塑在凝结线粒体形成中的作用，然后 建立凝结线粒体支持Acrosomes的生物发生的机制。我们的 应用依赖于尖端技术，例如稳定的同位素，冷冻 - 电子显微镜断层扫描和带有同位标记的定量蛋白质组学。拟议的研究是 重要的是因为它将确定CL重塑的机制和功能，这是一个广泛保守的 不确定意义的反应，并且因为它将建立BS的病理机制。