Cluster phases of membrane proteins

TL;DR

This paper proposes a physical model explaining the formation of small, stable protein clusters in cell membranes due to specific interactions, impacting membrane organization and diffusion, with implications for lipid rafts.

Contribution

It introduces a numerical investigation of cluster phases in membrane proteins based on colloidal suspension models, highlighting the role of protein interactions in cluster stability.

Findings

Proteins form stable small clusters due to short-range attraction and long-range repulsion.

Cluster formation influences membrane organization and protein diffusion.

The model connects cluster phases with lipid raft behavior.

Abstract

A physical scenario accounting for the existence of size-limited submicrometric domains in cell membranes is proposed. It is based on the numerical investigation of the counterpart, in lipidic membranes where proteins are diffusing, of the recently discovered cluster phases in colloidal suspensions. I demonstrate that the interactions between proteins, namely short-range attraction and longer-range repulsion, make possible the existence of stable small clusters. The consequences are explored in terms of membrane organization and diffusion properties. The connection with lipid rafts is discussed and the apparent protein diffusion coefficient as a function of their concentration is analyzed.