EXTRACELLULAR MATRIX NERVE TERMINAL ANCHORAGE PROTEINS

细胞外基质神经末梢锚定蛋白

• 批准号: 3404636
• 负责人: STEVEN Scott CARLSON
• 金额: $ 11.17万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-07-01 至 1988-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3404636
• 关键词: chromatography; electrophoresis; extracellular matrix; hybridomas; immunochemistry; membrane activity; monoclonal antibody; nerve endings; proteoglycan; radioassay; surface antigens; synapses; synaptic vesicles; tissue /cell culture; ultracentrifugation

No presynaptic membrane proteins which anchor nerve terminals to the extracellular matrix (ECM) are known. The goal of my proposed research is to identify and characterize some of these proteins involved with anchoring nerve terminals. Such proteins could mediate the well-known trophic interactions between the nerve terminal and basal lamina during nerve regeneration. Of special interest, therefore, will be those proteins that are specific for a subgroup of synapses. We have identified a proteoglycan from elasmobranch electric organ which has some of the characteristics of such an anchoring protein. It is found on the nerve terminal surface restricted to the synaptic region. It is tightly bound to and enriched in an extracellular matrix (ECM) fraction. Intriguingly, this proteoglycan contains an antigenic determinant which is only associated with the electric organ neurons. Finally, synaptic vesicles also contain a transmembrane proteoglycan which shares this antigenic determinant. Thus, synaptic vesicles also might contain this same proteoglycan. From this data we hypothesize that this proteoglycan is presynaptic membrane protein which links the nerve terminal to the ECM. In addition, the synaptic vesicles may act as vehicles for shuttling this molecule to and from the nerve terminal surface. This research proposal has two basic goals: 1) to determine the validity of the above hypothesis; 2) to identify and characterize other presynaptic membrane proteins which anchor the synaptic ECM. To accomplish the first goal several steps are required. We will determine whether the proteoglycan is an integral membrane protein by the presence or absence of a hydrophobic tail. We will identify the ECM components which bind the proteoglycan. If the proteoglycan is an integral membrane protein and binds ECM components, it must link the nerve terminal to the matrix. If this linkage is through the pathway specific antigenic determinant, this linkage could be specific to this synapse. A biochemical comparison of the synaptic vesicle and ECM proteoglycan protein cores will determine whether these two molecules could share a precursor-product relationship. To achieve the second goal we will use the ECM fraction, in which the nerve terminal proteoglycan was originally found. We will isolate a subfraction containing the integral membrane proteins contained in this ECM material. If presynaptic membrane proteins (other than the proteoglycan) bind to the ECM, they should be present in this subfraction. By making monoclonal antibodies against this subfraction, we should be able to identify them.

没有锚定神经末端的突触前膜蛋白 细胞外基质（ECM）是已知的。 我提出的研究的目的是 识别和表征与锚定有关的其中一些蛋白质 神经终端。 这种蛋白质可以介导众所周知的营养 神经末端和基底层之间的相互作用 再生。 因此，特别感兴趣的是那些蛋白质 是特定于突触子组的特定于。 我们已经从Elasmobranch电源器官中确定了一个蛋白聚糖，该蛋白酶可以 具有这种锚定蛋白的某些特征。 找到它 在神经末端表面限于突触区域。 这是 紧密结合并富集在细胞外基质（ECM）部分中。 有趣的是，该蛋白聚糖含有一种抗原决定因素 仅与电器官神经元相关。 最后，突触 囊泡还包含跨膜蛋白聚糖，该蛋白聚糖共享 抗原决定因素。 因此，突触囊泡也可能包含 相同的蛋白聚糖。 从这些数据中，我们假设该蛋白聚糖是突触前的 将神经末端与ECM联系起来的膜蛋白。 此外， 突触囊泡可以充当将此分子穿上的车辆 并从神经末端表面。 该研究建议有两个基本目标：1）确定有效性 上述假设； 2）识别和表征其他突触前的 锚定突触ECM的膜蛋白。 要完成第一个目标，需要几个步骤。 我们将确定 蛋白聚糖是否是存在或 没有疏水性尾巴。 我们将确定ECM组件 绑定蛋白聚糖。 如果蛋白聚糖是整体膜蛋白 并结合ECM组件，必须将神经终端连接到基质。 如果这种连接是通过途径特异性抗原决定因素的 连锁可能是该突触的特定的。 生化比较 突触囊泡和ECM蛋白聚糖蛋白核将确定是否确定 这两个分子可以共享前体产物关系。 到 实现第二个目标，我们将使用ECM的分数，在其中 最初发现末端蛋白聚糖。 我们将隔离一个子段 包含该ECM材料中包含的整体膜蛋白。 如果突触前膜蛋白（蛋白聚糖除外）与 ECM，它们应该存在于此子段中。 通过制作单克隆 针对该亚段的抗体，我们应该能够识别它们。