Packaging and Axonal Transport of Three Macromolecules

这项研究计划旨在定位两种特定的蛋白质在细胞体和神经轴突的内膜系统中。这些蛋白质的定位将阐明神经细胞的内膜系统参与了蛋白质包装，这些蛋白质被送往不同的表面膜或细胞外空间的靶区。要研究的两个靶蛋白是：1)Na+-K+ATPase；2)乙酰胆碱酯酶(AChE)。这些蛋白质将在光学和电子显微镜观察到的特定抗体探针的帮助下进行定位。这两种蛋白质在调节与神经细胞之间的通讯相关的电和化学活动方面很重要。所研究的膜系统既包括细胞体的膜系统，也包括轴突的膜系统。在细胞体中，要研究的膜系统涉及膜蛋白或分泌产物的生物合成和包装。在轴突中，至少有三个不同的膜系统，其功能或关系目前尚不清楚。最近针对每种蛋白质的特定抗体的产生和表征使得对这些蛋白质的生物合成和运输的研究成为可能，这些抗体可以用作探针，使用光学和电子显微镜技术相结合地标记每种蛋白质。最终，这项研究计划的活动将提供一张亚细胞路径图，两种不同分子形式的大分子，在神经冲动和突触传递中至关重要，沿着这些分子形式被运输到各自的目的地，最后结合并插入到它们的功能位置。这项研究使用了每种蛋白质分布的特定探针，将确定轴突不同形态的膜系统之间的功能关系。作为这些研究的结果，我们将对调节这些重要大分子的生命周期的细胞机制有更好的了解。

This research program is designed to localize two specific proteins within internal membrane systems of both the cell body and the nerve axon. Localization of these proteins will elucidate the involvement of the nerve cells' internal membrane systems in the packaging of proteins destined for different target areas of the surface membrane or extracellular space. The two target proteins to be studied are : 1) the Na+ - K+ ATPase; and 2) acetylcholinesterase (AChE). These proteins will be localized with the aid of specific antibody probes visualized by light and electron microscopy. These two proteins are important in regulating the electrical and chemical activities associated with communication between nerve cells. The membrane systems under study are both those of the cell body and of the axon. In the cell body, the membrane systems to be studied are involved in the biosynthesis and packaging of membrane proteins or secretion products. In the axon, there are at least three distinct membrane systems whose functions or relationship are not known at this time. Investigations into the biosynthesis and transport of these proteins are permitted by the recent production and characterization of specific antibodies to each that may be used as probes to label each using a combination of light and electron microscopic techniques. Ultimately, the activities of this research program will provide a map of the subcellular pathways along which differing molecular forms of two macromolecules, crucially involved in nerve impulse and synaptic transmission, are transported to their respective destinations and finally combined and inserted into their functional positions. This investigation, using specific probes for the distribution of each protein, will define the functional relationship between morphologically differing membrane systems of the axon. As a result of these studies we will gain a greater understanding of the cellular mechanisms which regulate the life cycle of these important macromolecules.***