Marxen M, Maienschein V, Volknandt W, Zimmermann H
Biozentrum der J. W. Goethe-Universität, Frankfurt am Main, Germany.
Neurochem Res. 1997 Aug;22(8):941-50. doi: 10.1023/a:1022414607385.
The distribution of the three synaptic vesicle proteins SV2, synaptophysin and synaptotagmin, and of SNAP-25, a component of the docking and fusion complex, was investigated in PC12 cells by immunocytochemistry. Colloidal gold particle-bound secondary antibodies and a preembedding protocol were applied. Granules were labeled for SV2 and synaptotagmin but not for synaptophysin. Electron-lucent vesicles were labeled most intensively for synaptophysin but also for SV2 and to a lesser extent for synaptotagmin. The t-SNARE SNAP-25 was found at the plasma membrane but also at the surface of granules. Labeling of Golgi vesicles was observed for all antigens investigated. Also components of the endosomal pathway such as multivesicular bodies and multilamellar bodies were occasionally marked. The results suggest that the three membrane-integral synaptic vesicle proteins can have a differential distribution between electron-lucent vesicles (of which PC12 cells may possess more than one type) and granules. The membrane compartment of granules appears not to be an immediate precursor of that of electron-lucent vesicles.
通过免疫细胞化学方法，在PC12细胞中研究了三种突触小泡蛋白SV2、突触素和突触结合蛋白，以及对接和融合复合体的一个组分SNAP-25的分布情况。采用了胶体金颗粒结合的二抗和包埋前方案。颗粒被标记为SV2和突触结合蛋白，但未被标记为突触素。电子透明小泡被标记为突触素的程度最高，但也被标记为SV2，而被标记为突触结合蛋白的程度较低。t-SNARE蛋白SNAP-25在质膜上被发现，也在颗粒表面被发现。观察到所有被研究抗原均标记了高尔基体小泡。内体途径的组分如多囊泡体和多板层体偶尔也被标记。结果表明，三种膜整合突触小泡蛋白在电子透明小泡（PC12细胞可能拥有不止一种类型）和颗粒之间可能具有不同的分布。颗粒的膜区室似乎不是电子透明小泡膜区室的直接前体。
