Ryan T A, Li L, Chin L S, Greengard P, Smith S J
Stanford University Medical School, California 94305, USA.
J Cell Biol. 1996 Sep;134(5):1219-27. doi: 10.1083/jcb.134.5.1219.
The synapsins are a family of four neuron-specific phosphoproteins that have been implicated in the regulation of neurotransmitter release. Nevertheless, knock-out mice lacking synapsin Ia and Ib, family members that are major substrates for cAMP and Ca2+/ Calmodulin (CaM)-dependent protein kinases, show limited phenotypic changes when analyzed electrophysiologically (Rosahl, T.W., D. Spillane, M. Missler, J. Herz, D.K. Selig, J.R. Wolff, R.E. Hammer, R.C. Malenka, and T.C. Sudhof. 1995. Nature (Lond.). 375: 488-493; Rosahl, T.W., M. Geppert, D. Spillane, D., J. Herz, R.E. Hammer, R.C. Malenka, and T.C. Sudhof. 1993. Cell. 75:661-670; Li, L., L.S. Chin, O. Shupliakov, L. Brodin, T.S. Sihra, O. Hvalby, V. Jensen, D. Zheng, J.O. McNamara, P. Greengard, and P. Andersen. 1995. Proc. Natl. Acad. Sci. USA. 92:9235-9239; see also Pieribone, V.A., O. Shupliakov, L. Brodin, S. Hilfiker-Rothenfluh, A.J. Czernik, and P. Greengard. 1995. Nature (Lond.). 375:493-497). Here, using the optical tracer FM 1-43, we characterize the details of synaptic vesicle recycling at individual synaptic boutons in hippocampal cell cultures derived from mice lacking synapsin I or wild-type equivalents. These studies show that both the number of vesicles exocytosed during brief action potential trains and the total recycling vesicle pool are significantly reduced in the synapsin I-deficient mice, while the kinetics of endocytosis and synaptic vesicle repriming appear normal.
突触结合蛋白是一个由四种神经元特异性磷蛋白组成的家族,它们与神经递质释放的调节有关。然而,缺乏突触结合蛋白Ia和Ib(这两个家族成员是环磷酸腺苷(cAMP)和钙/钙调蛋白(CaM)依赖性蛋白激酶的主要底物)的基因敲除小鼠,在进行电生理分析时表现出有限的表型变化(罗萨尔,T.W.,D. 斯皮兰,M. 米斯勒,J. 赫茨,D.K. 塞利格,J.R. 沃尔夫,R.E. 哈默,R.C. 马伦卡,以及T.C. 苏德霍夫。1995年。《自然》(伦敦)。375: 488 - 493;罗萨尔,T.W.,M. 格佩特,D. 斯皮兰,D.,J. 赫茨,R.E. 哈默,R.C. 马伦卡,以及T.C. 苏德霍夫。1993年。《细胞》。75: 661 - 670;李,L.,L.S. 钦,O. 舒普利亚科夫,L. 布罗丁,T.S. 西赫拉,O. 瓦尔比,V. 詹森,D. 郑,J.O. 麦克纳马拉,P. 格林加德,以及P. 安德森。1995年。《美国国家科学院院刊》。92: 9235 - 9239;另见皮耶里博内,V.A.,O. 舒普利亚科夫,L. 布罗丁,S. 希尔菲克 - 罗滕弗勒,A.J. 切尔尼克,以及P. 格林加德。1995年。《自然》(伦敦)。375: 493 - 497)。在此,我们使用光学示踪剂FM 1 - 43,对源自缺乏突触结合蛋白I的小鼠或野生型对照小鼠的海马细胞培养物中单个突触小体处的突触囊泡循环细节进行了表征。这些研究表明,在短暂动作电位串期间胞吐的囊泡数量以及总的循环囊泡池在缺乏突触结合蛋白I的小鼠中均显著减少,而内吞作用和突触囊泡再装填的动力学似乎正常。