Section: New Results

Model of membrane domains emergence

HA Soula, A Coulon, G Beslon (Beagle)

In the classical view, cell membrane proteins undergo isotropic random motion, that is a 2D Brownian diffusion that should result in an homogeneous distribution of concentration. It is, however, far from the reality: Membrane proteins can assemble into so-called microdomains (sometimes called lipid rafts) which also display a specific lipid composition. The amount of this so-called overconcentration at equilibrium is simply related to the ratio of diffusion coefficients between zones of high and low diffusion. Expanding the model to include particle interaction, we show that inhomogeneous diffusion can impact particles clusterization as well. The clusters of particles were more numerous and appear for a lower value of interaction strength in the zones of low diffusion compared to zones of high diffusion. Provided we assume stable viscosity heterogeneity in the membrane, our model proposes a simple mechanism to explain particle concentration heterogeneity and hence domains.