PROTEOMIC MAPPING OF MYELIN AND ITS MEMBRANE SUBDOMAINS

描述（来自申请人的摘要）：髓磷脂是一种动态的、功能性的 活性膜，对包括轴突在内的环境敏感。期间 在髓鞘形成中，它以惊人的数量产生。这是一个两极分化的 膜，具有宏观和微观结构。积极维护 其独特的结构和与轴突的特殊关系。在其有趣的 生物化学性质是高浓度的特定鞘糖脂， 特别是半乳糖苷（GalC）和硫苷脂。半乳糖脂具有 与少突胶质细胞分化的调节密切相关 和髓磷脂维持。 结合胆固醇，目前的证据表明，这些脂质 能够形成微区，其中一组离散的蛋白质成为 为了实现通常与信号相关的专门功能， 转导虽然有相当少的“主要”髓鞘蛋白是 认识到，有大量的数量识别不佳的“次要” proteins.人们对这两个类的功能知之甚少。本长期 这个应用程序的目标是开发一个数据库的总补充 髓鞘蛋白质组，并开始的任务， 与这些结构/代谢组分中的每一个一起起作用。 这将通过首先显示总髓鞘蛋白来实现 补体作为二维凝胶电泳图谱，并鉴定 通过免疫标记、非Edman质谱法测定单个成员，以及 生物信息学这些信息将为该项目提供一个数据库 和髓磷脂生物学社区。第二，将进行详细分析 在髓鞘的糖鞘磷脂-胆固醇微结构域中的蛋白质中， 将它们与总髓鞘蛋白质组相关联。一项研究将由他们的 组织，并将测试假设，提出有一个 可区分的微区的镶嵌。第三，这些信息将用于 研究这些微区的功能生物学。小鼠模型， 不产生半乳糖苷脂和硫化物（CGT缺失小鼠） 将在其微域方面进行分析。在这只老鼠中， Ranvier改变;我们提出的是这些分子的相关性 形态学的变化，我们已经表明，协会的一个离散的一组 具有鞘糖脂微结构域的蛋白质被改变。我们终于有 显示髓鞘-少突胶质细胞糖蛋白（MOG）分配到这些 微区，和实验刺激其进入成熟 少突胶质细胞导致特定的酪氨酸磷酸化， proteins.这与抗OMOG介导的过敏反应的关系 将考虑脑脊髓炎。 预计从这些调查中得出的概念将有助于 更好地了解髓鞘的生物发生，维护和正常功能，并帮助 设计范例，以促进髓鞘稳定性和髓鞘再生， 硬化症

DESCRIPTION (From the Applicant's Abstract):Myelin is a dynamic, functionally active membrane, sensitive to its environment including axons. During myelinogenesis, it is produced in prodigious quantities. It is a polarized membrane, with both macro- and microdomain organization. It actively maintains its unique structure and special relationship with axons. Among its interesting biochemical properties is a high concentration of specific glycosphingolipids, in particular galactocerebroside (GalC) and sulfatide. The galactolipids have been strongly implicated in the regulation of oligodendrocyte differentiation and myelin maintenance. In combination with cholesterol, current evidence indicates that these lipids are able to form microdomains in which a discrete set of proteins become associated in order to effect specialized functions often related to signal transduction. While a rather small number of "major" myelin proteins are recognized, there is a plethora of poorly identified quantitatively "minor" proteins. The function of both classes is poorly understood. This long term goal of this application is to develop a data base of the total complement of myelin proteins the Myelin Proteome, and to begin the task of associating function with each of these structural/metabolic components. This will be accomplished by first displaying the total myelin protein complement as a two-dimensional gel electrophoretic map, and identifying the individual members by immunolabeling, non-Edman mass spectrometry, and bioinformatics. This information will provide a database both for this project and for the myelin biology community. Second, a detailed analysis will be made of the proteins in the glycosphinogolipid-cholesterol microdomains of myelin, relating them to the total myelin proteome. A study will be made of their organization, and a hypothesis will be tested that proposes that there is a mosaic of distinguishable microdomains. Third, this information will be used to investigate the functional biology of these microdomains. A mouse model in which galactosylcerebroside and sulfide are not produced (the CGT-null mouse) will be analyzed in terms of its microdomains. In this mouse the nodes of Ranvier are altered; in what we propose are the molecular correlates of these morphological changes, we have shown that the association of a discrete set of proteins with the glycosphinogolipid microdomains is altered. Finally, we have shown that myelin-oligodendrocyte glycoprotein (MOG) partitions into these microdomains, and the experimental stimulation its entry in maturing oligodendrocytes results in the rapid tyrosine phosphorylation of specific proteins. The relationship of this to antiOMOG mediated allergic encephalomyelitis will be considered. It is expected that concepts derived from these investigations will help to better understand myelin biogenesis, maintenance and normal function, and help to design paradigms to promote myelin stability and remyelination in multiple sclerosis.