MYELIN ASSEMBLY AND ITS GENETIC DISORDER

这些研究使用针对以下目标的设计来检查髓鞘组装 蛋白质脂蛋白这两种完整蛋白质的胞内加工 (PLP)和髓鞘相关糖蛋白(MAG)。我们将使用体外培养技术 活动性髓鞘小鼠组织切片体系的建立 脑干。不同的标记方案和特定的抑制剂将 用来描绘细胞内的行程和CO-和 翻译后修饰，特别是PLP和PLP的酰化 MAG的糖基化。在不同的环境中通过的动力学 亚细胞细胞器(半衰期和周转率)将揭示 PLP和MAG遵循相同或不同的细胞内途径，并且 无论是相同的还是不同的机制调节它们的细胞内 运输。我们将使用特定的蛋白质糖基化抑制剂来 分块处理MAG的不同阶段以确定其作用 低聚糖部分在蛋白质的分类和运输中的作用。 以遗传为特征的髓鞘障碍小鼠突变体震颤 72P MAG低表达和67P MAG多肽高表达，以及 它们的异常糖基化将成为研究血管紧张素转换酶的有用的生物探针。 MAG在髓鞘形成中的调节作用。MAG代谢异常可能 是颤抖的主要障碍。我们将学习联合和 MAG多肽在细胞器中的翻译后加工 深入了解他们在装配过程中的代谢关系(S)。在……里面 此外，我们将探索MAG的一级结构是否有可能 多肽在震动时会发生变化。 我们相信，这些研究将导致关于 控制髓鞘形成的生化事件。一旦髓鞘的作用机制 鞘的形成是理解的，治疗可以被开发来加强 多发性硬化症等疾病中的再髓鞘形成。

These studies examine myelin assembly employing designs directed at intracellular processing of two integral proteins, proteolipid protein (PLP) and myelin associated glycoprotein (MAG). We will use an in vitro system of tissue slices prepared from actively myelinating murine brainstem. Different labeling protocols and specific inhibitors will be used to delineate the intracellular itinerary and the sites of co- and posttranslational modifications, specifically acylation of PLP and glycosylation of MAG. The kinetics of passage through different subcellular organelles (half-lifes and turn-over rates) will reveal whether PLP and MAG follow the same or different intracellular pathways, and whether the same or different mechanisms regulate their intracellular transport. We will employ specific inhibitors of protein glycosylation to block processing of MAG at different stages in order to determine the role of the oligosaccharide moiety in the sorting and trafficking of proteins. The dysmyelinating mouse mutant quaking which is characterized by genetic underexpression of 72p MAG and overexpression of 67p MAG polypeptides, and their abnormal glycosylation will be a useful biological probe to study the regulatory role of MAG in myelinogenesis. The aberrant MAG metabolism may be the primary disorder in quaking. We will study co- and posttranslational processing of MAG polypeptides in cellular organelles to gain insight into their metabolic relationship(s) during assembly. In addition, we will explore the possibility that the primary structure of MAG polypeptides are altered in quaking. We believe that these studies will lead to new concepts regarding the biochemical events controlling myelination. Once the mechanisms of myelin sheath formation are understood, therapies can be developed to potentiate remyelination in such diseases as multiple sclerosis.