OLIGODENDROCYTE/MYELIN GLYCOPROTEIN AND THE P

神经胶质细胞分化的调控及神经胶质细胞轴突的机制 相互作用和髓鞘形成是积极研究的领域。我有过 少突胶质细胞-髓磷脂糖蛋白的特征 中枢神经系统(CNS)中的OMgp。时间-空间 OMGp的表达与中枢神经系统尾-吻轴的关系 髓鞘形成。通过OMGp的结构，可以深入了解 中枢神经系统髓鞘形成中这种作用的基础机制。OMGp包含 一个富含亮氨酸重复序列(LRR)结构域，与 蛋白质-蛋白质相互作用及其翻译后修饰 包括糖基-磷脂酰肌醇(GPI)附着物。的确有 越来越多的证据表明，GPI锚在激活 酪氨酸激酶通路，在某些情况下定位于 腔泡泡。 最近的观察和我们的初步数据表明，OMgp是 存在于外周神经系统(PNS)，尤其是在 髓鞘的结旁区域，由髓鞘雪旺表达 细胞。我们对OMGp在形成和发展过程中的作用很感兴趣 三叉神经节髓鞘的维持。我们推测OMGp的表达方式是 髓鞘雪旺细胞具有同样的发育受限 在CNS中以OMGp的形式表达。凭借其LRRS和GPI膜 锚，我们假设OMGp与其他多肽相互作用， 例如轴突或其他细胞和/或自由配体上的受体。我们 我相信这些相互作用会导致酪氨酸激酶的激活 和下游通路的磷酸化在雪旺细胞中起重要作用 髓鞘形成。 当前提案的目的是描述OMGp的特点 在发育中的雪旺细胞中表达，以鉴定分子 它们与OMGp相互作用，以探索由此产生的激活 酪氨酸激酶通路，并检测转染组的效果 缺少LRRS或GPI锚点的OMgp的突变形式 这些小路。我们有四个具体目标： 1.检测OMgp在周围神经发育过程中的表达。 2.检测OMGp在雪旺细胞中的体外表达， 3.鉴定与OMGp相互作用的多肽，并鉴定 OMGp在信号转导中的作用 4.创建突变的Omgp结构：i)缺少LRR结构域，或ii) 以跨膜形式存在，并将这些突变形式的OMGp 变成永生的雪旺细胞。比较多克隆的能力 抗OMgp抗体诱导髓鞘表型和/或 天然与突变型OMGp中酪氨酸激酶通路的激活 转基因细胞。

The control of glial differentiation, and the mechanisms of glia-axon interactions and myelination are areas of active investigation. I have previously characterized the oligodendrocyte-myelin glycoprotein (OMgp) in the central nervous system (CNS). The temporal-spatial expression of OMgp correlates with the caudal-rostral axis of CNS myelination. The structure of OMgp provides insight into the mechanisms which underlie this role in CNS myelination. OMgp contains a leucine-rich repeat (LRR) domain, which has been implicated in protein-protein interactions, and its post-translational modifications include a glycosyl-phosphatidylinositol (GPI) attachment. There is growing evidence that the GPI anchor plays a role in activation of tyrosine kinase pathways, which in some cases localizes within caveolar vesicles. Recent observations and our preliminary data indicate that OMgp is present in the peripheral nervous system (PNS), particularly at the paranodal regions of myelin, and is expressed by myelinating Schwann cells. We are interested in OMgp's role in the formation and maintenance of PNS myelin. We speculate that OMgp's expression by myelinating Schwann cells has the same restricted developmental expression as OMgp in the CNS. By virtue of its LRRs and GPI membrane anchor, we hypothesize that OMgp interacts with other polypeptides, such as receptors on axons or other cells and/or free ligands. We believe these interactions will result in tyrosine kinase activation and phosphorylation of downstream pathways important in Schwann cell myelination. The purpose of the current proposal is to characterize OMgp's expression within developing Schwann cells, to identify the molecules which interact with OMgp, to explore the resultant activation of tyrosine kinase pathways, and to examine the effects of transfected mutant forms of OMgp which lack either the LRRs or the GPI anchor on these pathways. We have four specific aims: 1. Determine OMgp expression during peripheral nerve development, 2. Examine in vitro expression of OMgp in Schwann cells, 3. Identify polypeptides which interact with OMgp and characterize the role of OMgp in signal transduction, and 4. Create mutant OMgp constructs which: i) lack the LRR domain, or ii) exist as a transmembrane form and transfect these mutant forms of OMgp into immortalized Schwann cells. Compare the ability of polyclonal anti-OMgp antibodies to induce a myelinating phenotype and/or to activate tyrosine kinase pathways in native vs. mutant OMgp transfected cells.