Ultrastructural localization of mint1 at synapses in mouse hippocampus
Ultrastructural localization of mint1 at synapses in mouse hippocampus
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DOI：
10.1046/j.1460-9568.2000.00200.x
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发表时间：
2000-08
影响因子：
3.4
通讯作者：
M. Okamoto;T. Matsuyama;M. Sugita
中科院分区：
文献类型：
--
作者：
M. Okamoto;T. Matsuyama;M. Sugita
Mint1和mint2是在寻找munc18-1蛋白配体的过程中分离出来的，munc18-1是突触囊泡胞吐所必需的神经元蛋白。薄荷蛋白家族在进化过程中一直高度保守，从秀丽隐杆线虫到哺乳动物都保留了下来。一些生物化学和遗传证据表明，mint1和它在秀丽隐杆线虫中的同源物LIN‐10在大脑突触中起作用。由于mint1的精确亚细胞位置尚不完全清楚，我们使用免疫染色法检查了mint1在小鼠大脑中的分布，包括突触的超微结构定位。在整个大脑中，包括大脑皮层、纹状体、海马、丘脑、基底神经节和小脑，均检测到强烈的、精细点状的mint1免疫标记。在分子层的大多数突触中，mint1在活跃区特别丰富，与突触前终末的突触囊泡的关联程度较低。相比之下，在突触后密度中，很少有突触表现出mint1免疫反应性，并且在突触前和突触后终端中没有突触双阳性。Mint1在突触前终末的分布与munc18-1重叠。这些定位结果与先前证明的生化相互作用一致，并强烈支持mint1在中枢神经系统突触囊泡胞吐和突触组织中的功能。
Mint1 and mint2 were isolated in the course of seeking the protein ligands to munc18–1, a neuronal protein essential for synaptic vesicle exocytosis. The mint family of proteins has been highly conserved in the course of evolution, being retained from C. elegans to mammals. Several lines of biochemical and genetic evidence have suggested that mint1 and LIN‐10, its homologue in C. elegans, function at synapses in the brain. Because the precise subcellular location of mint1 is incompletely known, we used immunostaining to examine the distribution of mint1 in the mouse brain including ultrastructural localization in synapses. Strong, finely punctate mint1 immunolabeling was detected throughout the brain, including cerebral cortex, striatum, hippocampus, thalamus, basal ganglia and cerebellum. At the most synapses in the molecular layer, mint1 was particularly abundant at the active zone and to a lesser extent in association with synaptic vesicles in the presynaptic terminals. In contrast, a very few synapses showed mint1 immunoreactivity in the postsynaptic density and there was no synapse double‐positive in presynaptic and postsynaptic terminals. Mint1 distribution within presynaptic terminals overlapped that of munc18–1. These localization results are consistent with previously demonstrated biochemical interactions and strongly support functions of mint1 in synaptic vesicle exocytosis and synaptic organization in the central nervous system.