Mechanochemical rules for shape-shifting filaments that remodel membranes

The sequential exchange of filament composition to increase filament curvature was proposed as a mechanism for how ESCRT-III polymers deform and cut membranes. The relationship between the filament composition and its mechanical effect is lacking. We develop a kinetic model for the assembly of composite filaments that includes protein-membrane adhesion, filament mechanics and membrane mechanics. We identify the physical conditions for such a membrane remodelling and show this mechanism is efficient because sequential polymer assembly lowers the energetic barrier for membrane deformation.