GLYCOPROTEINS CONTAINING PHOSPHOGLUCOSE IN NEURAL RETINA

鸡胚胎神经视网膜糖蛋白相关寡糖的研究 其中含有葡萄糖的磷酸二酯-甘露糖连接(ManPGlc)具有 最近被我们的实验室检测到，还有一种负责 磷酸二酯和一组多肽的合成 明确地认出他们。这项提案寻求在一个 在分子水平上，这些蛋白质在发育过程中经历的变化 并评估这些蛋白质在视网膜中可能发挥的作用 视觉系统的生理功能。我们将特别注意 考虑到这种独特的低聚糖可能作为一种 运输信号以分离这些糖蛋白用于轴浆 运输，一旦在细胞表面，这些糖蛋白就发挥作用 在神经元间识别中。 这项建议的具体目的是：一、继续深入研究 磷酸葡萄糖识别的视网膜糖蛋白受体 转移酶反应。研究将包括确定具体的 磷酸葡萄糖转移酶的活性及其鉴定 雏鸡视网膜、顶盖、视网膜受体凝胶的放射自显影分析 以及中枢神经系统的其他部分。II.继续我们对 鸡胚胎神经视网膜中的ManPGlc结合蛋白。建议数 研究包括对这些氨基酸序列的测定 多肽，以及它们彼此之间和以前的关系 描述了细胞表面蛋白连接素。三、确定 含ManPGlc的糖蛋白与细胞间的黏附， 最终，与神经元间突触的特异性有关。我们建议继续进行 细胞间识别的细胞间识别研究 外源添加这些蛋白质本身，它们的寡糖 类似物，或针对它们的抗体，用于体外检测 细胞间黏附。四、研究是否有可能 含有ManPGlc的低聚糖可能是 视网膜轴浆运输中某些糖蛋白的选择 神经节细胞。在神经视网膜上的实验将确定ManPGlc 携带磷酸二酯连接的结合蛋白和/或糖蛋白 葡萄糖是轴向运输的，如果是这样的话，确定 这种低聚糖与这一过程有关。

Glycoprotein-associated oligosaccharides from embryonic chick neural retina which contain glucose in phosphodiester-linkage to mannose (ManPGlc) have recently been detected by our laboratory, as has an enzyme responsible for the synthesis of the phosphodiester and a group of peptides that specifically recognize them. This proposal seeks to investigate at a molecular level the changes these proteins undergo during development of the retina and to assess the roles these proteins may play in the physiologic functions of the visual system. Particular attention will be paid to the possibility that this unique oligosaccharide functions as a trafficking signal to segregate these glycoproteins for axoplasmic transport, and that once on the cell surface these glycoproteins function in interneuronal recognition. The specific aims of this proposal are: I. To pursue further studies of the glycoprotein acceptors in retina recognized in the phosphoglucosyl transferase reaction. Studies will include determinations of the specific activities of the phosphoglucosyltransferase and identification by autoradiographic analyses of gels of its acceptors in chick retina, tectum, and other parts of the CNS. II. To continue our characterization of ManPGlc binding proteins in embryonic chick neural retina. The proposed studies include a determination of the amino acid sequences of these peptides, and of their relationships to one another and to the previously described cell-surface protein ligatin. III. To determine the importance of ManPGlc-containing glycoproteins to cell-to-cell adhesion and, ultimately, to interneuronal synaptic specificity. We propose to pursue studies of intercellular recognition by monitoring the effects of exogenously adding these proteins themselves, their oligosaccharide analogs, or antibodies directed against them, to in vitro assays for intercellular adhesion. IV. To examine the possibility that oligosaccharides containing ManPGlc may be an important feature in the selection of certain glycoproteins for axoplasmic transport in retinal ganglion cells. Experiments in neural retina will determine if the ManPGlc binding proteins and/or glycoproteins carrying phosphodiester-linked glucose are axonally transported and, if so, to determine the importance of this oligosaccharide to this process.