ALCOHOL INTERACTION WITH L1 CELL ADHESION MOLECULE

描述：酗酒仍然是一个主要的公共卫生问题， 每年数十亿美元的医疗并发症，事故， 与酒精相关的暴力，以及生产力的丧失。一种改进的分子 对酒精中毒发病机制及其神经学的认识 需要改善并发症的预防和治疗。精神性 观察到发育迟缓、脑积水和胼胝体发育不全。 无论是胎儿酒精综合征(Fas)还是携带基因突变的儿童 细胞黏附分子(CAM)L1基因。我们已经观察到了低 乙醇浓度(IC50 7 MM)抑制细胞与细胞间的相互作用 由LL介导，但对由相关的 分子，N-CAM。因为LL在长期中起着基础性的作用 增强、学习和神经系统发育、扰动 L1介导的细胞-细胞黏附和信号转导可能有助于记忆 酗酒者的精神障碍和Fas。我们建议使用选择性诱变技术 人L1基因表达谱研究乙醇抑制作用的分子基础 L1介导的细胞间黏附。我们将创建缺失突变体 人L1基因在乙醇敏感区域定位中的应用 L1介导的细胞黏附、酪氨酸激酶活性、轴突延长和 小脑迁移。接下来我们将表达这些L1缺失突变体 NIH/3T3成纤维细胞和细菌。我们将确定个人是否 黏附免疫球蛋白样(Ig)或纤维连接蛋白III型重复序列 L1的结构域(FN3)在表达时表现出乙醇敏感的粘附性 NIH/3T3细胞，然后将了解L1cDNA中的特定缺失 取消乙醇对LL介导的细胞黏附的抑制 形态发生。探讨跨膜区和细胞质结构域 是乙醇敏感性所必需的，我们将检查 乙醇对包被可溶性L1-FC嵌合体的壳聚糖球粘附性的影响。 为了了解乙醇敏感性是否存在于细胞外区域 L1，我们将构建乙醇不敏感的N-CAM和 通过交换细胞质/跨膜结构域和 这两个分子的胞外区域。我们的长期目标 是为了了解乙醇与LL相互作用的分子机制 和其他跨膜蛋白。这些知识将提高我们的 对胎儿酒精综合征发病机制的认识及认知 酗酒者的精神障碍，为更有效的预防和 这些疾病的治疗。

DESCRIPTION: Alcoholism remains a major public health problem, costing the nations billions annually through medical complications, accidents, alcohol-associated violence, and lost productivity. An improved molecular understanding of the pathogenesis of alcoholism and its neurological complications is needed to improve prevention and treatment. Mental retardation, hydrocephalus, and agenesis of the corpus callosum are observed both in fetal alcohol syndrome (FAS) and in children with mutations in the gene for the cell adhesion molecule (CAM) L1. We have observed that low concentrations of ethanol (IC50 7 mM) inhibit cell-cell interactions mediated by Ll, but have no effect on adhesion mediated by a related molecule, N-CAM. Because Ll plays a fundamental role in long-term potentiation, learning, and nervous system development, perturbation of L1-mediated cell-cell adhesion and signaling could contribute to memory disorders in alcoholics and FAS. We propose to use selective mutagenesis of the human cDNA for L1 to study the molecular basis for ethanol's inhibition of L1-mediated cell-cell adhesion. We will create deletion mutants of the human L1 cDNA for mapping ethanol-sensitive domains that influence L1-mediated cell adhesion, tyrosine kinase activity, neurite elongation, and cerebellar migration. We will next express these Ll deletion mutants in NIH/3T3 fibroblasts and bacteria. We will determine whether individual adhesive immunoglobulin-like (Ig) or fibronectin type III repeat homology domains (FN3) of L1 exhibit ethanol-sensitive adhesiveness when expressed in NIH/3T3 cells, and will then learn whether specific deletions in the L1 cDNA abolish ethanol's inhibition of Ll-mediated cell-cell adhesion and morphogenesis. To explore whether the transmembrane and cytoplasmic domains of L1 are required for ethanol sensitivity, we will examine the effects of ethanol on the adhesion of Covaspheres coated with soluble L1-Fc chimeras. To learn whether ethanol sensitivity resides in the extracellular domain of L1, we will construct chimeric molecules of ethanol-insensitive N-CAM and ethanol-sensitive Ll by swapping the cytoplasmic/transmembrane domains and the extracellular domains of these two molecules. Our long-term objective is to understand the molecular mechanism by which ethanol interacts with Ll and other transmembrane proteins. This knowledge will improve our understanding of the pathogenesis of fetal alcohol syndrome and cognitive disorders in alcoholics, paving the way for more effective prevention and treatment of these disorders.