Clathrin-dependent and clathrin-independent retrieval of synaptic vesicles in retinal bipolar cells
Clathrin-dependent and clathrin-independent retrieval of synaptic vesicles in retinal bipolar cells
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DOI：
10.1016/j.neuron.2005.05.004
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发表时间：
2005-06-16
期刊：
影响因子：
16.2
通讯作者：
Lagnado, L
中科院分区：
文献类型：
--
作者：
Jockusch, WJ;Praefcke, GJK;Lagnado, L
突触囊泡可以快速或缓慢地恢复，但这些动力学差异的分子基础尚未确定。我们现在表明，在视网膜双极细胞的突触末端，本质上不同的分子调节快慢内吞作用。在末端进行了膜回收的电容测量，在末端引入了多肽和蛋白质结构域来破坏已知的clathrin、AP2接头复合体和两栖动物蛋白的相互作用。所有这些操作都选择性地抑制了膜提取的慢相(时间常数约为10 S)，而保留了快相(类似S的时间常数)的完整。因此，强烈刺激后缓慢的内吞作用依赖于笼蛋白涂层膜的形成。在较弱的刺激后发生的快速内吞作用以一种不依赖于笼蛋白的方式恢复囊泡膜。所有的代偿性内吞作用都需要GTP水解，但只有一小部分释放的小泡准备进行快速的、不依赖于网囊的内吞作用。
Synaptic vesicles can be retrieved rapidly or slowly, but the molecular basis of these kinetic differences has not been defined. We now show that substantially different sets of molecules mediate fast and slow endocytosis in the synaptic terminal of retinal bipolar cells. Capacitance measurements of membrane retrieval were made in terminals in which peptides and protein domains were introduced to disrupt known interactions of clathrin, the AP2 adaptor complex, and amphiphysin. All these manipulations caused a selective inhibition of the slow phase of membrane retrieval (time constant similar to 10 s), leaving the fast phase (similar to 1 s) intact. Slow endocytosis after strong stimulation was therefore dependent on the formation of clathrin-coated membrane. Fast endocytosis occurring after weaker stimuli retrieves vesicle membrane in a clathrin-independent manner. All compensatory endocytosis required GTP hydrolysis, but only a subset of released vesicles were primed for fast, clathrinindependent endocytosis.