Otto H, Hanson P I, Chapman E R, Blasi J, Jahn R
Howard Hughes Medical Institute, Yale University Medical School, New Haven, CT 06510, USA.
Biochem Biophys Res Commun. 1995 Jul 26;212(3):945-52. doi: 10.1006/bbrc.1995.2061.
We investigated the effect of poisoning rat brain synaptosomes with botulinum neurotoxin A on the NSF-mediated disassembly of a complex consisting of syntaxin, SNAP-25 and synaptobrevin (fusion complex). Botulinum neurotoxin A specifically removes 9 amino acids from the C-terminus of SNAP-25 and efficiently blocks KCl-evoked glutamate release from synaptosomes. We report that truncated SNAP-25 is incorporated into the fusion complex of poisoned synaptosomes. The presence of truncated SNAP-25 does not interfere with the NSF-induced disassembly of the fusion complex. Also, the release of truncated SNAP-25 from the fusion complex is similar to that of the native SNAP-25. Since neither the formation of the complex nor its disassembly seems to be affected by the SNAP-25 fragment, this fragment is likely to block exocytosis by disrupting events between disassembly of the synaptosomal fusion complex and membrane fusion itself.
我们研究了用肉毒杆菌神经毒素A毒害大鼠脑突触体对NSF介导的由 syntaxin、SNAP-25 和突触囊泡蛋白（融合复合体）组成的复合体解体的影响。肉毒杆菌神经毒素A特异性地从SNAP-25的C末端去除9个氨基酸，并有效阻断KCl诱导的突触体谷氨酸释放。我们报告，截短的SNAP-25被纳入中毒突触体的融合复合体中。截短的SNAP-25的存在并不干扰NSF诱导的融合复合体解体。此外，截短的SNAP-25从融合复合体中的释放与天然SNAP-25的释放相似。由于复合体的形成和解体似乎都不受SNAP-25片段的影响，该片段可能通过破坏突触体融合复合体解体与膜融合本身之间的事件来阻断胞吐作用。
