Controlling Cargo Trafficking in Multicomponent Membranes*

Biological membranes typically contain a large number of different components dispersed in small concen-trations in the main membrane phase, including proteins, sugars, and lipids of varying geometrical properties. Most of these components do not bind the cargo. Here, we show that such “inert” components can be crucial for the precise control of cross-membrane trafficking. Using a statistical mechanics model and molecular dynamics simulations, we demonstrate that the presence of inert membrane components of small isotropic curvatures dramatically influences cargo endocytosis, even if the total spontaneous curvature of such a membrane remains unchanged. Our results suggest a robust and general method of controlling cargo trafficking by adjusting the membrane composition without needing to alter the concentration of receptors or the average membrane curvature. This study indicates that cells can prepare for any trafficking event by incorporating curved inert components in either of the membrane leaflets.

Refs:
T. Curk, P. Wirnsberger, J. Dobnikar, D. Frenkel, and A. Šarić, Nano Lett., 18, 5350–5356 (2018)
T. Curk, J. Dobnikar, and D. Frenkel, PNAS. 114, 7210–7215 (2017)