Aberrant Cardiolipin Dynamics in Barth Syndrome

巴斯综合征中异常的心磷脂动力学

• 批准号: 10385350
• 负责人: Michael Schlame
• 金额: $ 0.55万
• 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/10385350
• 关键词: 3-Methylglutaconic aciduria type 2; Address; Affect; Automobile Driving; Cardiolipins; Characteristics; Complex; Crista ampullaris; Crowding; Data; Development; Drosophila genus; Electrons; Energy Metabolism; Enzymes; Fatty Acids; Functional disorder; Germ Cells; Goals; Health; Human; Knowledge; Life; Lipids; Membrane; Metabolic Diseases; Microscopic; Mission; Mitochondria; Mitochondrial Diseases; Mitochondrial Membrane Protein; Molecular; Mus; Mutation; Organelles; Oxidative Phosphorylation; Pathologic; Phospholipids; Proteins; Proteomics; Public Health; Reaction; Role; Spermatogenesis; Stress; System; Techniques; Testing; United States National Institutes of Health; Work; Yeasts; body system; density; disability; experimental study; insight; lipid disorder; lipidome; membrane assembly; mitochondrial membrane; mitochondrial metabolism; 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 (i) identify the mechanism by which OXPHOS expression controls CL remodeling and (ii) establish the function of CL remodeling in membrane assembly. First, in order to identify the mechanism by which OXPHOS expression controls CL remodeling, we will determine the effect of OXPHOS assembly on the CL remodeling reaction, then identify the OXPHOS assembly step that is critical for CL remodeling, and finally determine whether protein crowding affects CL remodeling. Second, in order to establish the function of CL remodeling, we will determine the effect of CL remodeling on the density of OXPHOS complexes, on the stability of cristae membranes, and on the development of germ cell mitochondria. Germ cell mitochondria will be studied because our preliminary data suggest a specific role of CL remodeling and OXPHOS assembly in spermatogenesis. Experiments will be carried out in genetically modified yeast, Drosophila, and mice. Our application relies on cutting-edge techniques, such as lipidome- wide flux analysis with stable isotopes, cryo-electron microscopic tomography, and quantitative proteomics. 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（i）确定oxphos表达的机制 控制CL重塑，（ii）在膜组件中建立CL重塑的功能。首先，按顺序 为了确定Oxphos表达控制Cl重塑的机制，我们将确定效果 在Cl重塑反应上的Oxphos组装，然后确定关键的OXPHOS组装步骤 用于CL重塑，并最终确定蛋白质拥挤是否影响CL重塑。第二，为了 建立CL重塑的功能，我们将确定CL重塑对密度的影响 Oxphos复合物，关于Cristae膜的稳定性以及生殖细胞的发展 线粒体。将研究生殖细胞线粒体，因为我们的初步数据表明 精子发生中的Cl重塑和OXPHOS组装。实验将在遗传上进行 改良的酵母，果蝇和小鼠。我们的应用依赖于尖端技术，例如lipidome-- 通过稳定的同位素，冷冻电子显微镜断层扫描和定量蛋白质组学的广泛通量分析。 拟议的研究很重要，因为它将确定CL重塑的机制和功能，A 不确定意义的广泛保守反应，因为它将建立 BS。