Identification of synaptic vesicle-specific proteins and their physiological roles in synaptic transmission

突触囊泡聚集在突触前神经末梢内，含有神经递质物质，在突触传递过程中通过胞吐释放。突触囊泡的化学结构几乎是未知的，除了突触蛋白1，它与囊泡膜相关并解离，从而控制囊泡与突触前细胞膜的融合。为了鉴定其他囊泡特异性蛋白，我们从豚鼠大脑皮层中纯化了针对突触囊泡部分的单克隆抗体文库。四组不同的抗体分别鉴定出30、36、3和65千兆隆的四种囊泡特异性蛋白。我们将它们分别命名为SVP (synaptic vesicle protein) 30,36,38和65。与突触蛋白I不同，svp被整合在囊泡膜内。svp65在钙的存在下被磷酸化。SVP 38被认为与分别在西德和美国发现的synaptophysin和p38相同。用抗svp抗体对哺乳动物神经组织进行免疫组化，证实了中枢和周围神经系统突触发育和组织的几个方面。例如，小脑中各种突触发育的时间进程得到了证实。svp在突触传递中的生理作用有待进一步阐明。

Synaptic vesicles are clustered within the presynaptic nerve terminals and contain neurotransmitter substances which are released via exocytosis during the synaptic transmission. Chemical architecture of the synaptic vesicles remains almost unknown except for synapsin I which is associated and dissociated with the vesicle membrane and thus controls fusion of the vesicles with the presynaptic cell memmbrane. In order to identify other vesicle-specific proteins, we produced a library of monoclonal antibodies against synaptic vesicle fraction purified from the guinea pig cerebral cortex. Four different groups of the antibodies identified four vesicle specific proteins of 30, 36, 3, and 65 kilodalons. We named them SVP (synaptic vesicle protein) 30, 36, 38 and 65. Unlike synapsin I, SVPs were integrated within the vesicle membrane. SVP 65 were phosphorylated in the presence of calcium. SVP 38 was considered to be identical with synaptophysin and p38 which were independently discovered in West germany and the United States. Immunohistochemistry of the mammalisn nervous tissue with anti-SVP antibodies has demonstrated several aspects in development and organization of the synapses in the central and peripheral nervous system. For exzmple, time course of development of various synapses was confirmed in the cerebellum. Physiological roles of the SVPs in the synaptic transmission remain to be elucidated in future.