Finite size effects in non-equilibrium membrane phase separation

TL;DR

This study investigates how finite-size effects influence non-equilibrium membrane phase separation, revealing that system size tuning can control cluster sizes and optimize enzymatic reaction efficiency in cellular membranes.

Contribution

The paper introduces a combined stochastic and analytic approach to understand finite-size effects on membrane clustering and demonstrates how system size impacts reaction efficiency.

Findings

Tuning system size controls membrane heterogeneity.

Reaction efficiency varies non-monotonically with system size.

Optimal reaction conditions occur at sizes similar to cellular organelles.

Abstract

The formation of dynamical clusters of proteins is ubiquitous in cellular membranes and is in part regulated by the recycling of membrane components. Mean-field models of out-of-equilibrium cluster formation with recycling predict a broad cluster size distribution for infinite systems and must be corrected for finite-size effects for small systems such as cellular organelles. We show, using stochastic simulations and analytic modelling, that tuning the system size is an efficient way to control the size of lateral membrane heterogeneities. We apply these findings to a chain of enzymatic reaction sensitive to membrane protein clustering. The reaction efficiency is found to be a non-monotonic function of the system size, and can be optimal for sizes comparable to those of cellular organelles.