Membrane remodeling due to mixture of multiple curvature proteins

Abstract

We present an extension of the Monte Carlo based mesoscopic membrane model, where the membrane is represented as a dynamically triangulated surface and the proteins are modeled as anisotropic inclusions formulated as in-plane nematic field variables adhering to the deformable elastic sheet. In the extended model, we have augmented the Hamiltonian to study membrane deformation due to a mixture of multiple types of curvature generating proteins. This feature opens the door for understanding how multiple kinds of curvature-generating proteins may be working in a coordinated manner to induce desired membrane morphologies. For example, among other things, we study membrane deformations and tubulation due to a mixture of positive and negative curvature proteins as mimics of various proteins from BAR domain family. We also study the effect membrane anisotropy, which manifest as membrane localization and differential binding affinity of a given curvature protein, leading to insights into the tightly regulated cargo sorting and transport processes. Our simulation results show different morphology of deformed vesicles that depend on the curvatures and number of the participating proteins as well as on the protein-protein and membrane-proteins interactions. SignificanceMembrane remodeling requires highly orchestrated interactions between several types of lipids and curvature proteins. Experimentally probing the membrane deformation intermediates is non-trivial. For example, it is not known exactly how two or more different kinds of BAR domain proteins work in concert to induce and stabilize certain membrane curvatures. In this work, we use mesoscopic continuum modeling and explore the factors that induce and stabilize a range of membrane deformation due to a mixture of positive and negative curvature proteins.