Rolling blackout is required for synaptic vesicle exocytosis
Rolling blackout is required for synaptic vesicle exocytosis
复制标题
DOI：
10.1523/jneurosci.3770-05.2006
复制
发表时间：
2006-03-01
影响因子：
5.3
通讯作者：
Broadie, K
中科院分区：
文献类型：
--
作者：
Huang, FD;Woodruff, E;Broadie, K
滚动停电 (RBO) 是一种假定的跨膜脂肪酶，是果蝇神经元中磷脂酶 C 依赖性磷脂酰肌醇 4,5-二磷酸 - 二酰甘油信号传导所必需的。条件温度敏感 (TS) rbo 突变体在几分钟内表现出完全的、可逆的麻痹，这表明 RBO 是运动所必需的。 RBO 蛋白主要定位于神经肌肉接头 (NMJ) 突触的突触前束和整个中枢突触神经毡，rbo TS 突变体在几分钟内表现出中枢和外周突触传递的完全、可逆阻断。这种表型似乎仅限于成虫，因为幼虫 NMJ 不表现出急性阻断。成人 rbo TS 突变体 bouton 的电子显微镜显示，总突触小泡 (SV) 含量增加，伴随着突触前 bouton 大小的收缩，以及在几分钟内停靠在突触前活性区的 SV 的积累。基因测试揭示了rbo和syntaxin1A TS突变体之间的协同相互作用，表明RBO是N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）介导的SV胞吐作用机制中所必需的，或者是SV融合所需的平行途径中所必需的。 rbo TS 突变不会明显改变 SNARE 复合体的组装，这表明 SV 融合中存在下游需求。我们得出的结论是，RBO 在 SV 对接下游的神经递质释放中发挥着重要作用，可能介导 SV 融合。
Rolling blackout (RBO) is a putative transmembrane lipase required for phospholipase C-dependent phosphatidylinositol 4,5-bisphosphate - diacylglycerol signaling in Drosophila neurons. Conditional temperature-sensitive (TS) rbo mutants display complete, reversible paralysis within minutes, demonstrating that RBO is acutely required for movement. RBO protein is localized predominantly in presynaptic boutons at neuromuscular junction (NMJ) synapses and throughout central synaptic neuropil, and rbo TS mutants display a complete, reversible block of both central and peripheral synaptic transmission within minutes. This phenotype appears limited to adults, because larval NMJs do not manifest the acute blockade. Electron microscopy of adult rbo TS mutant boutons reveals an increase in total synaptic vesicle (SV) content, with a concomitant shrinkage of presynaptic bouton size and an accumulation of docked SVs at presynaptic active zones within minutes. Genetic tests reveal a synergistic interaction between rbo and syntaxin1A TS mutants, suggesting that RBO is required in the mechanism of N-ethylmaleimide-sensitive factor attachment protein receptor ( SNARE)- mediated SV exocytosis, or in a parallel pathway necessary for SV fusion. The rbo TS mutation does not detectably alter SNARE complex assembly, suggesting a downstream requirement in SV fusion. We conclude that RBO plays an essential role in neurotransmitter release, downstream of SV docking, likely mediating SV fusion.