权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Mitochondrial phosphatidylethanolamine metabolism

线粒体磷脂酰乙醇胺代谢

基本信息

批准号：
9266799
负责人：
Steven Michael Claypool
金额：
$ 36.59万
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/9266799
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 Elements Embryo Endoplasmic Reticulum Eukaryota Event Exercise Family Genes Genetic Goals Health Homeostasis Homology Modeling Impairment In Vitro Inner mitochondrial membrane Knowledge Life Lipids Malignant Neoplasms Mammals Mass Spectrum Analysis Membrane Membrane Proteins Metabolism Mitochondria Mitochondrial Proteins Modeling Molecular Morphology Mus Mutagenesis Organelles Outer Mitochondrial Membrane Pathologic Pathway interactions Phenotype Phosphatidylethanolamine Phosphatidylserines Phospholipid Metabolism Phospholipids Play Prion Diseases Production Prokaryotic Cells Protein Kinase Proteins Recombinants Regulation 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 virtual

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 β subunit that non-covalently interacts with the enzymatically essential small α subunit. How phosphatidylserine decarboxylase 1 achieves specificity is not known, but a potential substrate binding motif in the α 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 β and α subunits. The goal of this mapping exercise is to determine if the α/β 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丰富的磷脂成分，因此在细胞自主性和亚细胞区室化中发挥着重要作用。此外，PE 是其他主要脂质的前体，对于多种特定生物功能至关重要。在真核生物中，PE 合成可以通过四种不同的途径进行，其中之一是由位于线粒体内膜的磷脂酰丝氨酸脱羧酶 1 进行的。有趣的是，尽管有四种不同的途径可以产生 PE，但磷脂酰丝氨酸脱羧酶 1 的缺失在小鼠胚胎中是致命的。关于磷脂酰丝氨酸脱羧酶 1 机制知之甚少，该途径所需的大多数脂质运输步骤仍然不清楚，并且线粒体中产生的 PE 如何支持线粒体功能尚未完全解决。该应用的总体目标是开始填补我们关于这一重要生物合成途径的知识空白。在第一个具体目标中，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 的催化活性形式是通过自催化事件产生的，该自催化事件生成大的膜锚定 β 亚基，该亚基与酶促必需的小 α 亚基非共价相互作用。磷脂酰丝氨酸脱羧酶 1 如何实现特异性尚不清楚，但已通过同源建模鉴定了 α 亚基中的潜在底物结合基序。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 的另一项主要工作是利用化学交联来识别 β 和 α 亚基之间的相互作用表面。此绘图练习的目的是确定 α/β 相互作用对于磷脂酰丝氨酸脱羧酶 1 活性是否至关重要，如果是，又如何。磷脂酰丝氨酸脱羧酶 1 嵌入线粒体内膜中，已知线粒体外产生的 PE 无法弥补线粒体内产生的 PE 的缺失。在目标 2 中，我们将利用一种新颖的短路策略来更全面地了解线粒体 PE 代谢。具体来说，我们将确定外膜中产生的 PE 进入内膜的能力，从分子角度表征线粒体 PE 产生所需的运输步骤，并查明线粒体 PE 和心磷脂生物合成途径之间的合成致死相互作用是否反映了基本内膜或外膜功能的缺陷。通过更全面地了解线粒体 PE 代谢，可以为与 PE 相关的疾病（包括阿尔茨海默病和朊病毒病）以及与心磷脂代谢紊乱相关的多种病理状态（包括癌症）确定新的治疗靶点。