Complexin regulates the closure of the fusion pore during regulated vesicle exocytosis
Complexin regulates the closure of the fusion pore during regulated vesicle exocytosis
复制标题
DOI：
10.1074/jbc.c200166200
复制
发表时间：
2002-05-24
影响因子：
4.8
通讯作者：
Burgoyne, RD
中科院分区：
文献类型：
--
作者：
Archer, DA;Graham, ME;Burgoyne, RD
胞吐期间和整个细胞中的膜融合被认为涉及SNARE（可溶性N-乙基马来酰亚胺敏感性融合蛋白附着蛋白受体）蛋白质家族的成员。这些蛋白质组装成四螺旋束可能是双层融合的驱动力的一部分。调节胞吐在神经元和相关的细胞类型是专门的快速和Ca 2+依赖性，表明参与其他调节蛋白质的具体调节胞吐。其中包括复合蛋白，这是两种密切相关的蛋白质，仅与组装的陷阱复合物结合。我们研究了复杂的功能，通过分析单个囊泡释放事件在肾上腺嗜铬细胞，使用碳纤维安培法。这些细胞表达复合蛋白II，这种蛋白质的过表达改变了囊泡释放事件的动力学，使它们的时程缩短。这种效应依赖于复合物与SNARE复合物的相互作用，因为引入Arg-59的突变，该突变是一种与SNARE复合物中的突触泡蛋白相互作用的残基，消除了其效应。这些数据与复合蛋白在稳定SNARE复合物的中间体以允许胞吐囊泡的吻跑再循环中的功能一致。
Membrane fusion during exocytosis and throughout the cell is believed to involve members of the SNARE (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors) family of proteins. The assembly of these proteins into a four-helix bundle may be part of the driving force for bilayer fusion. Regulated exocytosis in neurons and related cell types is specialized to be fast and Ca2+-dependent suggesting the involvement of other regulatory proteins specific for regulated exocytosis. Among these are the complexins, two closely related proteins that bind only to the assembled SNARE complex. We have investigated the function of complexin by analysis of single vesicle release events in adrenal chromaffin cells using carbon fiber amperometry. These cells express complexin II, and overexpression of this protein modified the kinetics of vesicle release events so that their time course was shortened. This effect depended on complexin interaction with the SNARE complex as introduction of a mutation of Arg-59, a residue that interacts with synaptobrevin in the SNARE complex, abolished its effects. The data are consistent with a function for complexin in stabilizing an intermediate of the SNARE complex to allow kiss-andrun recycling of the exocytosed vesicle.