Physical mechanisms of micro- and nanodomain formation in multicomponent lipid membranes

TL;DR

This paper reviews physical mechanisms behind micro- and nanodomain formation in multicomponent lipid membranes, emphasizing lipid-driven processes, phase separation, and non-equilibrium effects, supported by theory, simulations, and experiments.

Contribution

It provides a comprehensive overview of lipid-driven mechanisms for domain formation, integrating theoretical, simulation, and experimental perspectives.

Findings

Lipid phase separation can lead to micro- and nanodomain formation.

Curvature-composition coupling stabilizes two-dimensional microemulsions.

Non-equilibrium effects like membrane recycling influence domain dynamics.

Abstract

This article summarizes a variety of physical mechanisms proposed in the literature, which can generate micro- and nanodomains in multicomponent lipid bilayers and biomembranes. It mainly focusses on lipid-driven mechanisms that do not involve direct protein-protein interactions. Specifically, it considers (i) equilibrium mechanisms based on lipid-lipid phase separation such as critical cluster formation close to critical points, and multiple domain formation in curved geometries, (ii) equilibrium mechanisms that stabilize two-dimensional microemulsions, such as the effect of linactants and the effect of curvature-composition coupling in bilayers and monolayers, and (iii) non-equilibrium mechanisms induced by the interaction of a biomembrane with the cellular environment, such as membrane recycling and the pinning effects of the cytoplasm. Theoretical predictions are discussed together with simulations and experiments. The presentation is guided by the theory of phase transitions and critical phenomena, and the appendix summarizes the mathematical background in a concise way within the framework of the Ginzburg-Landau theory.