NEUROBIOLOGY OF SULFATED GLUCURONYL GLYCOCONJUGATES

该项目的主要长期目标是了解 磺基葡萄糖醛酸基糖脂(SGGL)等新内酯系列的功能 糖脂是特定阶段的和发育调节的 中枢神经系统皮质中的抗原，在重要的 细胞分化和细胞迁移时期。碳水化合物部分 SGGL的一种是高度免疫原性的单抗，如HNK-1， 它们与碳水化合物结合也与相同或相似的 细胞内几种重要糖蛋白的表位 相互作用，如神经细胞黏附分子，N_cam，L1，J1， Tenascin、细胞肌动蛋白、整合素、尼罗河、髓鞘相关糖蛋白和PO 蛋白。神经系统的正常发育依赖于这些 分子。尽管SGGL在胚胎和胚胎的皮质中表达 仅限新生儿发育，它们与浦肯野细胞和在 周围神经系统，即使是成年人。目前的具体目标 是为了了解它们的差异的生化调节 通过研究酶在神经系统的这些区域中的表达 参与这些脂类的新陈代谢。酶包括几种 糖基转移酶和糖苷酶。除SGGL外，其他新乳糖系列 具有相同主链的糖脂，例如呋喃十八烷四糖苷和 神经节苷脂LD1也是发育调节的抗原 发育过程中大脑皮质的位置。表达特定基因的细胞 碳水化合物将在体外进行研究，以评估这些物质的作用 成熟和分化中的抗原。SGGL和硫脂起作用 配基细胞-细胞-细胞、细胞-底物和结合体之间的黏附 细胞外基质蛋白层粘连蛋白。计划进行研究，以确定 30kD的SGGL/硫脂结合蛋白来自发育中的皮质和 小脑。这种蛋白质和该蛋白质的抗体将被用作 探讨SGGL和HNK-1反应蛋白的作用 在细胞相互作用中。新的固定方法已经被开发出来 HNK-1活性脂的免疫细胞化学定位 而不是神经组织中的蛋白质。这种方法将被用来精确地 定位脂肪与蛋白质抗原的表达，在光和 在大脑皮质和小脑发育过程中的电子显微镜水平， 在某些突变体中。它们的细胞和亚细胞定位 分子可能为它们的功能作用提供新的线索。

The major long term goal of this project is to understand the role and function of sulfoglucuronyl glycolipids (SGGLs) and other neolacto series of glycolipids which are stage specific and developmentally regulated antigens in the cortex in the central nervous system, during the important period of cell differentiation and cell migration. The carbohydrate moiety of SGGLs is highly immunogenic and monoclonal antibodies such as HNK-1, which bind to the carbohydrate also react with either the same or similar epitope on several important glycoproteins involved in cellular interaction, such as neural cell adhesion molecules, N_CAMs, L1, J1, tenascin, cytotactin, integrin, NILE, myelin associated glycoprotein and PO protein. The proper development of the nervous system depends upon these molecules. Although SGGLs are expressed in the cortex during embryonic and neonatal development only, they are associated with Purkinje cells and in peripheral nervous system, even in the adult. The present specific aims are to understand the biochemical regulation of their differential expression in these areas of the nervous system by studying the enzymes involved in the metabolism of these lipids. Enzymes include several glycosyltransferases and glycosidases. Besides SGGLs other neolactoseries of glycolipids having the same backbone, such as fuconeolactotetraoside and ganglioside LD1 are also developmentally regulated antigens to their proper location in the cortex during development. Cells expressing specific carbohydrates will be studied in vitro to evaluate the role of these antigens in maturation and differentiation. SGGLs and sulfatide act as ligand cell-adhesion between cell-cell, cell-substratum and bind extracellular matrix protein laminin. Studies are planned to characterize a 30 kD SGGL/sulfatide binding protein from developing cortex and cerebellum. The protein and antibodies to this protein will be used as probes to investigate the role of SGGLs and of the HNK-1 reactive proteins in cellular interactions. New fixation method has been developed to differentiate immunocytochemical localization of HNK-1 reactive lipids versus proteins in neural tissues. This method will be used to precisely localize the expression of lipid versus protein antigens, at light and electron microscopic level during development of the cortex and cerebellum, and in certain mutants. Cellular and subcellular localization of these molecules may provide new clues as to their functional role.