Our first indication that epsin affected membrane curvature was the tubulation of PtdIns(4,5)P2 liposomes. Full-length epsin1 tubulates but only the ENTH domain is necessary. In the presence of clathrin, curvature is localised to regions of clathrin-polymerisation.
more monolayer images....
Thus we believe that epsin drives membrane curvature in a clathrin-coated pit.

Ford, M.G.J., Mills, I.G., Peter, B.J., Vallis, Y., Praefcke, G.J.K., Evans, P.R. and McMahon, H.T. (2002) Curvature of clathrin-coated pits driven by epsin. Nature 419: 361-366 (abstract). (.pdf) supplemental data

(see also News and Views and highlights in Nature Cell Biology, Nature reviews in molecular cell biology, and a mini review in Cell (Cell October 18, 2002: 111 (2):143-146)(summary)