High affinity interaction of syntaxin and SNAP-25 on the plasma membrane is abolished by botulinum toxin E
High affinity interaction of syntaxin and SNAP-25 on the plasma membrane is abolished by botulinum toxin E
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DOI：
10.1074/jbc.m310879200
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发表时间：
2004-01-02
影响因子：
4.8
通讯作者：
Davletov, B
中科院分区：
文献类型：
--
作者：
Rickman, C;Meunier, FA;Davletov, B
荷尔蒙和神经递质的释放需要含有货物的囊泡与质膜融合。这种胞吐过程依赖于三种SNARE蛋白，即靶细胞质膜上的Synaxin和SNAP-25以及囊泡膜上的Synaptobrevin。在这项研究中，我们研究了导致融合性SNAR复合体形成的分子组装途径。我们现在证明，质膜合成素和SNAP-25与高亲和力和等摩尔化学计量比相互作用，在通往三元SNARE复合体的途径上形成稳定的二聚体。在牛嗜铬细胞中，Synaxin和SNAP-25共定位于确定的簇中，平均直径为700 nm，覆盖了10%的质膜。肉毒杆菌神经毒素E是一种已知的神经麻痹药物，它可以去除SNAP-25的C末端，在体外解离靶标SNAR二聚体，并在体内扰乱SNAP-25的聚集。总之，我们的数据揭示了稳定的Synaxin/SNAP-25二聚体的形成是调控胞吐作用下SNARE组装途径的中心原理。
The release of hormones and neurotransmitters requires the fusion of cargo-containing vesicles with the plasma membrane. This process of exocytosis relies on three SNARE proteins, namely syntaxin and SNAP-25 on the target plasma membrane and synaptobrevin on the vesicular membrane. In this study we examined the molecular assembly pathway that leads to formation of the fusogenic SNARE complex. We now show that the plasma membrane syntaxin and SNAP-25 interact with high affinity and equimolar stoichiometry to form a stable dimer on the pathway to the ternary SNARE complex. In bovine chromaffin cells, syntaxin and SNAP-25 colocalize in defined clusters that average 700 nm in diameter and cover 10% of the plasma membrane. Removal of the C terminus of SNAP-25 by botulinum neurotoxin E, a known neuroparalytic agent, dissociates the target SNARE dimer in vitro and disrupts the SNARE clustering in vivo. Together, our data uncover formation of stable syntaxin/SNAP-25 dimers as a central principle of the SNARE assembly pathway underlying regulated exocytosis.