Littleton J T, Chapman E R, Kreber R, Garment M B, Carlson S D, Ganetzky B
Laboratory of Genetics, University of Wisconsin, Madison 53706, USA.
Neuron. 1998 Aug;21(2):401-13. doi: 10.1016/s0896-6273(00)80549-8.
The neuronal SNARE complex is formed via the interaction of synaptobrevin with syntaxin and SNAP-25. Purified SNARE proteins assemble spontaneously, while disassembly requires the ATPase NSF. Cycles of assembly and disassembly have been proposed to drive lipid bilayer fusion. However, this hypothesis remains to be tested in vivo. We have isolated a Drosophila temperature-sensitive paralytic mutation in syntaxin that rapidly blocks synaptic transmission at nonpermissive temperatures. This paralytic mutation specifically and selectively decreases binding to synaptobrevin and abolishes assembly of the 7S SNARE complex. Temperature-sensitive paralytic mutations in NSF (comatose) also block synaptic transmission, but over a much slower time course and with the accumulation of syntaxin and SNARE complexes on synaptic vesicles. These results provide in vivo evidence that cycles of assembly and disassembly of SNARE complexes drive membrane trafficking at synapses.
神经元SNARE复合体是通过突触小泡蛋白与 syntaxin 和 SNAP-25 的相互作用形成的。纯化的SNARE蛋白会自发组装，而拆卸则需要ATP酶 NSF。有人提出组装和拆卸循环驱动脂质双层融合。然而，这一假设仍有待在体内进行验证。我们分离出了果蝇 syntaxin 中的一个温度敏感型麻痹突变体，该突变体在非允许温度下会迅速阻断突触传递。这种麻痹突变特异性且选择性地减少了与突触小泡蛋白的结合，并消除了 7S SNARE 复合体的组装。NSF（昏迷）中的温度敏感型麻痹突变也会阻断突触传递，但时间进程要慢得多，并且突触小泡上会积累 syntaxin 和 SNARE 复合体。这些结果提供了体内证据，表明 SNARE 复合体的组装和拆卸循环驱动突触处的膜运输。
