海兔神经系统中钙激活且对pH敏感的环磷酸腺苷磷酸二酯酶

Ca2+ activated and pH sensitive cyclic AMP phosphodiesterase in the nervous system of the mollusc Pleurobranchaea.

作者信息

Calhoon R D, Gillette R

出版信息

Brain Res. 1983 Jul 25;271(2):371-4. doi: 10.1016/0006-8993(83)90304-9.

Abstract

Regulation of cyclic AMP through its synthesis is known to be important in modulating the activity of molluscan neurons; however, no data exists regarding the regulation of cyclic AMP degradation. We find that cyclic AMP phosphodiesterase (PDE) activity in homogenates of the nervous system of the mollusc Pleurobranchaea is significantly stimulated by calcium ion. Ca2+ stimulation is suppressed by the calmodulin antagonist trifluoperazine (TFP), indicating resemblance to the Ca2+-calmodulin PDEs of mammalian neurons. Ca2+ also accentuates the pH sensitivity of PDE. The qualities of Ca2+ and pH sensitivity of PDE are fitted into a model for cAMP regulation of neuronal activity in an identified feeding command neuron; the postulated role of PDE is consistent with effects of cAMP, TFP, and pH on the neuron's activity.

摘要

已知通过环磷酸腺苷（cAMP）合成来调节其水平对于调节软体动物神经元的活性很重要；然而，关于环磷酸腺苷降解的调节尚无相关数据。我们发现，软体动物侧鳃神经节神经系统匀浆中的环磷酸腺苷磷酸二酯酶（PDE）活性受到钙离子的显著刺激。钙调蛋白拮抗剂三氟拉嗪（TFP）可抑制钙离子的刺激作用，这表明其与哺乳动物神经元的钙调蛋白依赖性磷酸二酯酶相似。钙离子还增强了磷酸二酯酶对pH的敏感性。磷酸二酯酶对钙离子和pH的敏感性特征符合一个已鉴定的摄食指令神经元中cAMP对神经元活性调节的模型；磷酸二酯酶的假定作用与cAMP、TFP和pH对该神经元活性的影响一致。