Pattern formation, localized and running pulsation on active spherical membranes

Abstract

Active force generation by actin-myosin cortex coupled to the cell membrane allows the cell to deform, respond to the environment, and mediate cell motility and division. Several membrane-bound activator proteins move along it and couple to the membrane curvature. Besides, they can act as nucleating sites for the growth of filamentous actin. Actin polymerization can generate a local outward push on the membrane. Inward pull from the contractile actomyosin cortex can propagate along the membrane via actin filaments. We use coupled evolution of fields to perform linear stability analysis and numerical calculations. As activity overcomes the stabilizing factors such as surface tension and bending rigidity, the spherical membrane shows instability towards pattern formation, localized pulsation, and running pulsation between poles. We present our results in terms of phase diagrams and evolutions of the coupled fields. They have relevance for living cells and can be verified in experiments on artificial cell-like constructs.

main text and ESI, total 20 pages and 19 figures; version accepted for publication in Soft Matter

References in corpus (5)

• Topology and Dynamics of Active Nematic Vesicles
• Fluid pumping and active flexoelectricity can promote lumen nucleation in cell assemblies
• Covariant Active Hydrodynamics of Shape-Changing Epithelial Monolayers
• Actin filaments growing against an elastic membrane: Effect of membrane tension
• Interplay between surface and bending energy helps membrane protrusion formation