Possible role of phospholipid nanotubes in directed transport of membrane vesicles

We indicate that membrane nanotubes may have an important role in directed transport of membrane vesicles between different membrane-enclosed compartments in cells. We present experimental evidence that small blebs of phospholipid nanotube may travel along the nanotube and act as vehicles for transporting the enclosed solution. We have also observed similar small membrane blebs of a long membrane tube in red blood cells. In both cases the small vesicles seem to be a distended integral part of the membrane tube and not independent vesicles entrapped within the tube. (C) 2003 Elsevier Science B.V. All rights reserved.