McMahon H T, Wigge P, Smith C
Neurobiology Division, MRC-LMB, Cambridge, UK.
FEBS Lett. 1997 Aug 18;413(2):319-22. doi: 10.1016/s0014-5793(97)00928-9.
Amphiphysin is an SH3 domain protein that has been implicated in synaptic vesicle endocytosis. We have recently cloned a second amphiphysin isoform, Amph2 (sequence submitted to GenBank, Y13380). Proteins capable of forming a complex with amphiphysin were isolated from rat brain by using recombinant GST-Amph2 for binding experiments. As well as interacting with dynamin I, the full-length protein bound to a weaker 180-kDa band. Immunoblotting demonstrated this protein to be clathrin. To address whether this is a direct interaction, the clathrin binding to amphiphysin was reconstituted in vitro with purified proteins. The N-terminal domain of Amph2 is sufficient for clathrin binding. Dynamin, which interacts with the SH3 domain of Amph2, displaces clathrin from the N-terminus. We propose a model that may explain how clathrin and dynamin are recruited to non-overlapping sites of the coated pit.
发动蛋白结合蛋白是一种含有SH3结构域的蛋白质，它与突触小泡内吞作用有关。我们最近克隆了第二种发动蛋白结合蛋白异构体，即发动蛋白结合蛋白2（Amph2，其序列已提交至GenBank，登录号为Y13380）。通过使用重组GST - Amph2进行结合实验，从大鼠脑中分离出了能够与发动蛋白结合蛋白形成复合物的蛋白质。除了与发动蛋白I相互作用外，全长蛋白还与一条较弱的180 kDa条带结合。免疫印迹显示该蛋白为网格蛋白。为了确定这是否是直接相互作用，用纯化的蛋白在体外重建了网格蛋白与发动蛋白结合蛋白的结合。发动蛋白结合蛋白2的N端结构域足以与网格蛋白结合。与发动蛋白结合蛋白2的SH3结构域相互作用的发动蛋白，会将网格蛋白从N端取代。我们提出了一个模型，该模型或许可以解释网格蛋白和发动蛋白是如何被募集到被膜小窝的不重叠位点的。
