Mechanics and polarity in cell motility

Abstract

The motility of a fish keratocyte on a flat substrate exhibits two distinct regimes: the non-migrating and the migrating one. In both configurations the shape is fixed in time and, when the cell is moving, the velocity is constant in magnitude and direction. Transition from a stable configuration to the other one can be produced by a mechanical or chemotactic perturbation. In order to point out the mechanical nature of such a bistable behaviour, we focus on the actin dynamics inside the cell using a minimal mathematical model. While the protein diffusion, recruitment and segregation govern the polarization process, we show that the free actin mass balance, driven by diffusion, and the polymerized actin retrograde flow, regulated by the active stress, are sufficient ingredients to account for the motile bistability. The length and velocity of the cell are predicted on the basis of the parameters of the substrate and of the cell itself. The key physical ingredient of the theory is the exchange among actin phases at the edges of the cell, that plays a central role both in kinematics and in dynamics.

References in corpus (4)

• Spontaneous division and motility in active nematic droplets
• Collective dynamics of actomyosin cortex endow cells with intrinsic mechanosensing properties
• Mechanics of motility initiation and motility arrest in crawling cells
• Optimality of contraction-driven crawling

Cited by in corpus (7)

• Mechanical stress as a regulator of cell motility
• Review: How dynamic prestress governs the shape of living systems, from the subcellular to tissue scale
• Cell crawling on a compliant substrate: a biphasic relation with linear friction
• Cell motility as an energy minimization process
• Initiation of motility on a compliant substrate
• Stability, convergence, and sensitivity analysis of the Filament Based Lamellipodium Model and the corresponding FEM
• Modelling cell-cell collision and adhesion with the Filament Based Lamellipodium Model