Regulation of Mitochondrial Division by Phosphatidic Acid

磷脂酸对线粒体分裂的调节

• 批准号: 10241320
• 负责人: Hiromi Sesaki
• 金额: $ 31.11万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 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 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10241320
• 关键词: Alzheimer' s Disease; Basic Science; Binding; Biochemical; Biology; Biophysics; Cell Death; Cells; Cellular Assay; Chemicals; Cytosol; Data; Disease; Dissociation; Dynamin; Ensure; Eukaryotic Cell; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Health; Human; Huntington Disease; Hydrolysis; Intervention; Knock-out; Link; Lipids; Mass Spectrum Analysis; Medical; Medicine; Membrane; Metabolism; Mitochondria; Modeling; Mutation; Organelles; Outcome; Outer Mitochondrial Membrane; Parkinson Disease; Pathogenesis; Pharmacology; Phosphatidic Acid; Phospholipase D; Phospholipids; Play; Polymers; Production; Proteins; Regulation; Role; Signal Transduction; Site; System; Testing; Textbooks; Work; constriction; innovation; insight; lipidomics; mitochondrial membrane; mutant; nervous system disorder; novel; overexpression; proteoliposomes; receptor; recruit

Abstract Mitochondria are ubiquitous organelles in eukaryotic cells that play important roles in energy production, metabolism, signal transduction and cell death. These functions require precise control of mitochondrial division, and altered mitochondrial division has been linked to many neurological diseases. A key protein involved in mitochondrial division is dynamin-related protein 1 (Drp1), a mechano-chemical GTPase that constitutes the mitochondrial division machinery. Drp1 is a soluble protein recruited to mitochondria from the cytosol by Drp1 receptor proteins located on mitochondria. After being recruited, Drp1 polymerizes into higher- order oligomers. Drp1 oligomers then drive the constriction of mitochondria. In the textbook model, mitochondrial division is regulated when Drp1 is recruited and oligomerized onto mitochondria. In contrast to this current view, our recent work suggested a major mechanism by which the timing of the constriction is regulated after Drp1 is oligomerized on mitochondria. This new mechanism involves novel interactions of Drp1 with the signaling phospholipid phosphatidic acid (PA) along with saturated phospholipids in the mitochondrial outer membrane. We suggest that these lipid interactions inhibit the GTPase activity of Drp1 oligomers and thereby control the initiation of the membrane constriction. In addition, we found that a mitochondrial, PA-producing phospholipase D, MitoPLD, directly binds Drp1 and inhibits mitochondrial division. This result suggests that PA is locally created in the vicinity of the division machinery. This local PA production may ensure robust spatial regulation of Drp1. These findings led to the hypothesis that PA inhibits Drp1 and the dissociation of Drp1 from MitoPLD activates mitochondrial division. In this proposed study, we will critically test this hypothesis and further develop and adjust it in an informed way. In Aim 1, we will determine how PA changes Drp1 activity using innovative biochemical, biophysical and cellular assays. We will also analyze how the mitochondrial lipid composition changes during division using lipidomics. In Aim 2, we will decipher how Drp1-MitoPLD interactions modulate the activity of both Drp1 and MitoPLD in mitochondrial division and how Drp1-MitoPLD interactions are regulated. We will also determine how MitoPLD controls the lipid composition in mitochondria. We expect that the outcomes of this proposed study will significantly advance the important biology of phospholipids and organelle dynamics and produce critical insights into human health and diseases.

抽象的 线粒体是真核细胞中无处不在的细胞器，在能源生产中起重要作用， 代谢，信号转导和细胞死亡。这些功能需要精确控制线粒体 分裂和线粒体分裂的改变与许多神经系统疾病有关。关键蛋白 与线粒体分裂有关的是与动力蛋白相关的蛋白1（DRP1），这是一种机械化学GTPase 构成线粒体分区机械。 DRP1是一种可溶性蛋白，可从 DRP1受体蛋白位于线粒体上的DRP1受体蛋白。招募后，DRP1聚合成较高的 订购低聚物。然后，DRP1低聚物驱动线粒体的收缩。在教科书模型中， 当募集DRP1并将其低聚到线粒体上时，线粒体分裂受到调节。 与当前的观点相反，我们最近的工作提出了一种主要机制 在线粒体上将DRP1寡聚后，收缩受到调节。这种新机制涉及小说 DRP1与信号磷脂磷脂酸（PA）与饱和磷脂的相互作用 在线粒体外膜中。我们建议这些脂质相互作用抑制了GTPase活性 DRP1低聚物，从而控制膜收缩的启动。此外，我们发现 线粒体，产生PA的磷脂酶D，mitopld直接结合DRP1并抑制线粒体分裂。 该结果表明，PA是在部门机械附近本地创建的。这个当地的PA生产 可以确保DRP1的强大空间调节。这些发现导致了以下假设：PA抑制DRP1和 DRP1与MITOPLD的解离会激活线粒体分裂。 在这项拟议的研究中，我们将对这一假设进行批判性检验，并进一步开发和调整它 方式。在AIM 1中，我们将使用创新的生化，生物物理和 细胞测定。我们还将分析线粒体脂质组成在分裂期间使用 脂质组学。在AIM 2中，我们将解释DRP1-Mitopld相互作用如何调节DRP1和 线粒体分裂中的线粒体以及如何调节DRP1-Mitopld相互作用。我们还将确定 Mitopld如何控制线粒体中的脂质组成。我们期望这一提议的结果 研究将显着提高磷脂和细胞器动力学的重要生物学，并产生 对人类健康和疾病的批判性见解。