Recapitulation of cell-like KRAS4b membrane dynamics on complex biomimetic membranes

Understanding the spatiotemporal distribution and dynamics of RAS on the plasma membrane (PM) is the key for elucidating the molecular mechanisms of the RAS signaling pathway. Single particle tracking (SPT) experiments show that in cells, KRAS diffuses in at least three interchanging states on the cellular PM; however, KRAS remains monomeric and always shows homogeneous diffusion on artificial membranes. Here, we show for the first time on a supported lipid bilayer composed of heterogeneous lipid components that we can recapitulate the three-state diffusion of KRAS seen in cells. The use of a biologically relevant eight-lipid system opens a new frontier in the biophysical studies of RAS and other membrane associated proteins on a biomimetic system that recapitulates the complexity of a cellular PM. [Display omitted] •KRAS4b shows homogeneous diffusion on simple 2-lipids bilayer•KRAS4b shows a cell-like, three-state diffusion on a complex 8-lipid bilayer•Phase separation in lipids favors the multi-state diffusion of KRAS4b•The complex lipid composition favors RAS nanoclustering irrespective of nucleotide state Molecular biology; Membrane architecture; Biomimetics; Biotechnology; Biophysics