Simulations of membrane tubulation by lattices of amphiphysin N-BAR domains.

Membrane compartments of manifold shapes are found in cells, often sculpted by cellular proteins. In particular, proteins of the BAR domain superfamily participate in membrane-sculpting processes in vivo and reshape also in vitro low-curvature membrane liposomes into high-curvature tubes and vesicles. Here we show by means of computer simulations totaling over 1 millisecond, how lattices involving parallel rows of amphiphysin N-BAR domains sculpt flat membranes into tubes. A highly detailed, dynamic picture of the 100-microsecond formation of membrane tubes by lattices of N-BAR domains is obtained. Lattice types inducing a wide range of membrane curvatures, with radii approximately 15-100 nm, are explored. The results suggest that multiple lattice types are viable for efficient membrane bending.