Chapter 15 - LLPS and regulation of transmembrane signaling

Abstract

Liquid–liquid phase separation (LLPS) processes with different dimensions may be distinguished. 3D condensation occurs in aqueous solution and leads to membrane-less organelle formation. 2D films may be formed near membrane surfaces, and lateral phase separation (membrane rafts) occurs within the membranes themselves. Here, we propose a model in which the processes of phase separation in membranes (2D structures) and LLPS in the volume (3D structures) influence each other. Moreover, we hypothesized that LLPS in the volume may propagate across the membrane due to stimulation of membrane raft formation, which mediate LLPS on the other side of the membrane. Separated liquid phase may be the site of signaling complexes assembly, or phase transition may propagate further intracell or intraorganelle space. LLPS on the membranes represents a previously poorly explored signaling mechanism, which allows quickly and with low amount of energy regulate cellular functions and metabolism.