Clusters of proteins in bio-membranes: insights into the roles of interaction potential shapes and of protein diversity

TL;DR

This study uses Monte Carlo simulations to explore how interaction potential shapes and protein diversity influence the formation and biological functions of protein clusters in bio-membranes, revealing their generic nature and functional advantages.

Contribution

It demonstrates that cluster phases are robust across different potential models and shows how protein diversity affects cluster composition and biological responses.

Findings

Cluster phases are generic across various interaction potentials.

Protein clusters selectively recruit specific protein species.

Cluster formation enhances cell response to external stimuli.

Abstract

It has recently been proposed that proteins embedded in lipidic bio-membranes can spontaneously self-organize into stable small clusters, or membrane nano-domains, due to the competition between short-range attractive and longer-range repulsive forces between proteins, specific to these systems. In this paper, we carry on our investigation, by Monte Carlo simulations, of different aspects of cluster phases of proteins in bio-membranes. First, we compare different long-range potentials (including notably three-body terms) to demonstrate that the existence of cluster phases should be quite generic. Furthermore, a real membrane contains hundreds of different protein species that are far from being randomly distributed in these nano-domains. We take this protein diversity into account by modulating protein-protein interaction potentials both at short and longer range. We confirm theoretical predictions in terms of biological cluster specialization by deciphering how clusters recruit only a few protein species. In this respect, we highlight that cluster phases can turn out to be an advantage at the biological level, for example by enhancing the cell response to external stimuli.