Mitochondrial phosphatidylethanolamine metabolism

线粒体磷脂酰乙醇胺代谢

基本信息

批准号：
8749989
负责人：
Steven Michael Claypool
金额：
$ 30.78万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2018-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8749989
关键词：
Address Alzheimer&apos s Disease Binding Binding Sites Biochemical Biological Biological Process Biology CDP ethanolamine Carboxy-Lyases Cardiolipins Catalysis Chemicals Complement Computer Simulation Cysteine Defect Disease Endoplasmic Reticulum Eukaryota Event Exercise Family Genes Genetic Goals Health Homeostasis Homology Modeling In Vitro Indium Inner mitochondrial membrane Knowledge Life Lipids Malignant Neoplasms Mammals Maps Mass Spectrum Analysis Membrane Metabolism Mitochondria Mitochondrial Membrane Protein Mitochondrial Proteins Modeling Molecular Morphology Mus Mutagenesis Organelles Outer Mitochondrial Membrane Pathway interactions Phenotype Phosphatidylethanolamine Phosphatidylserines Phospholipid Metabolism Phospholipids Play Prion Diseases Production Prokaryotic Cells Protein Kinase C Proteins Recombinants Regulation Relative (related person)Role Saccharomyces cerevisiae Site Specificity Substrate Specificity Surface Testing Yeasts base cardiolipin synthase cell growth crosslink insight lipid transport mutant new therapeutic target novel public health relevance respiratory tool trafficking

项目摘要

DESCRIPTION (provided by applicant): The importance of phosphatidylethanolamine (PE) in biology is multi-faceted. PE is typically the second most abundant phospholipid component in biological membranes and thus plays a fundamental role in cellular autonomy and subcellular compartmentalization. In addition, PE is a precursor for other major lipids and is critical for a diverse range of specific biological functions. In eukaryotes, PE synthesis can occur via four separate pathways one of which is performed by phosphatidylserine decarboxylase 1 which resides in the inner mitochondrial membrane. Intriguingly, even though there are four distinct pathways to make PE, deletion of phosphatidylserine decarboxylase 1 is embryonically lethal in mice. Not much is known about the phosphatidylserine decarboxylase 1 mechanism, most of the lipid trafficking steps required for this pathway remain obscure, and how PE produced in mitochondria supports mitochondrial function is incompletely resolved. The overarching goal of this application is to begin filling in the numerous gaps in our knowledge about this essential biosynthetic pathway. In the first specific aim, we will identify functionally important structural motifs in phosphatidylserine decarboxylase 1. The catalytically active form of phosphatidylserine decarboxylase 1 is generated by an autocatalytic event that generates a large membrane anchored ??subunit that non-covalently interacts with the enzymatically essential small ? subunit. How phosphatidylserine decarboxylase 1 achieves specificity is not known, but a potential substrate binding motif in the ? subunit has been identified by homology modeling. One goal of Aim 1 is to test the generated homology model and define the substrate binding motif. Another major effort in Aim 1 is to utilize chemical crosslinking to identify the interactio surface between the ? and ? subunits. The goal of this mapping exercise is to determine if the ? /?? interaction is critical for phosphatidylserine decarboxylase 1 activity, and if so, how. Phosphatidylserine decarboxylase 1 is embedded in the mitochondrial inner membrane and it is known that PE produced outside of mitochondria is unable to compensate for the absence of PE made in mitochondria. In Aim 2, we will exploit a novel short-circuit strategy to obtain a more comprehensive understanding of mitochondrial PE metabolism. Specifically, we will determine the ability of PE produced in the outer membrane to access the inner membrane, molecularly characterize trafficking steps required for mitochondrial PE production, and pinpoint if the synthetic lethal interaction between the mitochondrial PE and cardiolipin biosynthetic pathways reflects a defect in an essential inner membrane or outer membrane function. By obtaining a more comprehensive understanding of mitochondrial PE metabolism, novel therapeutic targets may be identified for those diseases in which PE has been implicated, including Alzheimer's and prion disease, and for the numerous pathological states, including cancer, associated with derangements in cardiolipin metabolism.

描述（由申请人提供）：磷脂酰乙醇胺（PE）在生物学中的重要性是多方面的。 PE通常是生物膜中第二大丰富的磷脂成分，因此在细胞自主性和亚细胞分区化中起着基本作用。此外，PE是其他主要脂质的前体，对于各种特定的生物学功能至关重要。在真核生物中，PE合成可以通过四个独立的途径进行，其中一种是由磷脂酰甲酯脱羧酶1进行的，该辅助辅助酶1位于内部线粒体膜中。有趣的是，即使有四个不同的途径可以使PE进行PE，但磷脂酰丝氨酸脱羧酶1的缺失在小鼠中也是胚胎致死的。对于磷脂酰丝氨酸脱羧酶1机制，该途径所需的大多数脂质运输步骤仍然晦涩难懂，线粒体中的PE如何支持线粒体功能是不完全解决的。该应用程序的总体目标是开始填补我们有关这种基本生物合成途径的众多差距。在第一个特定目标中，我们将确定功能上重要的结构磷脂酰丝氨酸脱羧酶1中的基序。磷脂酰丝氨酸脱羧酶1的催化活性形式是由自催化事件产生的，该事件会产生一个大膜锚定的？非共价相互作用的大膜锚定。亚基。磷脂酰丝氨酸脱羧酶1如何达到特异性，而是潜在的底物结合基序？亚基已通过同源模型确定。目标1的目标之一是测试生成的同源模型并定义底物结合基序。目标1的另一个主要努力是利用化学交联来识别？和？亚基。此映射练习的目的是确定是否？ /??相互作用对于磷脂酰丝氨酸脱羧酶1的活性至关重要，如果是，则如何。磷脂酰丝氨酸脱羧酶1嵌入线粒体内膜中，众所周知，在线粒体外产生的PE无法补偿线粒体中的PE缺失。在AIM 2中，我们将利用一种新颖的短路策略来获得对线粒体PE代谢的更全面的理解。具体而言，我们将确定在外膜中访问内膜内部膜的PE产生的能力，分子表征了线粒体PE产生所需的运输步骤，并确定是否在线粒体PE和心cardiolipin生物合成途径之间的合成致死相互作用是否反映了基本的内膜或外膜外膜或外膜外膜的缺陷。通过对线粒体PE代谢有更全面的了解，可以确定那些与PE相关的疾病（包括阿尔茨海默氏症和prion病）的新型治疗靶标，以及在众多的病理状态（包括与心脏磷脂代谢中的疾病相关的癌症）。