CLATHRIN INTERACTS SPECIFICALLY WITH AMPHIPHYSIN AND IS DISPLACED BY DYNAMIN

Amphiphysin is an SH3 domain protein that has been implicated in synap tic vesicle endocytosis, We have recently cloned a second amphiphysin isoform, Amph2 (sequence submitted to GenBank, Y13380), Proteins capab le of forming a complex,vith amphiphysin were isolated from rat brain by using recombinant GST-Amph2 for binding experiments. As well as int eracting 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 holy clathrin and dynamin are recruited to non-overlapping sites of the coated pit, (C) 1997 Federation of European Biochemical Societies.