ROLE OF CYCLIC ADP-RIBOSE IN CALCIUM DISPOSITION IN NG108-15 CELLS

拟议研究的总体目标是确定 环腺苷二磷酸核糖(CADPR)在钙稳态调节中的作用 NG108细胞，神经细胞系。Cadpr是一种自然产生的 核苷酸被发现是一种有效的钙释放介质 细胞内存储。该建议的具体目标是：(1) NG 108细胞内钙池的特征，(2)到 研究NG108细胞中cADPR合成酶和降解酶的特性， (3)鉴定NG108细胞中cADPR结合蛋白(S)；(4) 探讨NG108细胞内源性cADPR水平的调控 细胞。NG108细胞内的钙池将被探测 使用洗涤剂通透性细胞或纯化的微粒子和 以cADPR、咖啡因和肌醇的能力为特征 三磷酸释放储存的钙。《红楼梦》的特点 合成、降解和结合cADPR的蛋白质将通过 它们的亚细胞定位、调节和纯化的研究。 对cADPR细胞内浓度的调节将是 通过在各种已知条件下测量cADPR来检查 细胞内钙离子。细胞内浓度的调节 钙在所有细胞中都是一个关键过程。在神经细胞中， 钙离子的变化在许多神经元中起着重要作用 包括神经递质释放在内的过程，在 细胞骨架、基因表达和一系列代谢事件。近期 有证据表明cADPR可能是一种内源性调节因子。 钙诱导钙释放，其作用机制类似于 咖啡因。咖啡因是一种强大的中枢神经刺激剂。 系统，并可能因为这个行动，是最广泛的 在世界上使用过的毒品。咖啡因刺激大脑的机制 对中枢神经系统的认识还不完全。因为cADPR出现了 成为咖啡因敏感型钙释放的内源性调节剂 神经元中cADPR功能和代谢的系统研究 细胞应该提供关于刺激中枢神经系统的有用信息 神经系统。

The overall objective of the proposed research is to define the role of cyclic ADP-ribose (cADPR) in the regulation of calcium homeostasis in NG108 cells, a neuronal cell line. cADPR is a naturally occurring nucleotide found to be a potent mediator of calcium release from intracellular stores. The specific aims of the proposal are: (1) to characterize intracellular calcium pools in NG 108 cells, (2) to characterize the cADPR synthetic and degradative enzymes in NG108 cells, (3) to characterize the cADPR binding protein(s) in NG108 cells, and (4) to examine the regulation of the endogenous level of cADPR in NG108 cells. The intracellular pools of calcium in NG108 cells will be probed using detergent permeabilized cells or purified microsomes and characterized in terms of the ability of cADPR, caffeine and inositol trisphosphate to release stored calcium. The characterization of the proteins that synthesize, degrade and bind cADPR will be achieved through studies on their subcellular localization, regulation, and purification. The regulation of the intracellular concentration of cADPR will be examined by measuring cADPR under a variety of conditions known to raise intracellular calcium. The regulation of the intracellular concentration of calcium is a critical process in all cells . In neuronal cells, changes in calcium play an important role in a number of neuronal processes including neurotransmitter release, changes in the cytoskeleton, gene expression and a number of metabolic events. Recent evidence suggests that cADPR may be the endogenous modulator of calcium-induced calcium release and act through a mechanism similar to caffeine. Caffeine is a powerful stimulant of the central nervous system, and probably because of this action, is one of the most widely used drugs in the world. The mechanism by which caffeine stimulates the central nervous system is not completely understood. Since cADPR appears to be the endogenous modulator of calcium release from caffeine-sensitive stores, a systematic study of cADPR function and metabolism in neuronal cells should provide useful information on stimulation of the central nervous system.