Fission of a Multiphase Membrane Tube

TLDR

Intracellular transport often relies on membrane deformations that form buds, yet the influence of membrane inhomogeneities on these processes remains poorly understood. The study examines how lipid‑rich membrane domains affect the shape and fate of membrane tubes. The model shows that lipid phase separation drives tube fission via elastic constant differences and predicts fission time scales that match experiments.

Abstract

A common mechanism for intracellular transport is the use of controlled deformations of the membrane to create spherical or tubular buds. While the basic physical properties of homogeneous membranes are relatively well known, the effects of inhomogeneities within membranes are very much an active field of study. Membrane domains enriched in certain lipids, in particular, are attracting much attention, and in this Letter we investigate the effect of such domains on the shape and fate of membrane tubes. Recent experiments have demonstrated that forced lipid phase separation can trigger tube fission, and we demonstrate how this can be understood purely from the difference in elastic constants between the domains. Moreover, the proposed model predicts time scales for fission that agree well with experimental findings.