A free-boundary model of a motile cell explains turning behavior

Masoud Nickaeen, Igor L. Novak, Stephanie Pulford, Aaron Rumack, Jamie Brandon, Boris M. Slepchenko, Alexander Mogilner

Research output: Contribution to journalArticle

Abstract

To understand shapes and movements of cells undergoing lamellipodial motility, we systematically explore minimal free-boundary models of actin-myosin contractility consisting of the force-balance and myosin transport equations. The models account for isotropic contraction proportional to myosin density, viscous stresses in the actin network, and constant-strength viscous-like adhesion. The contraction generates a spatially graded centripetal actin flow, which in turn reinforces the contraction via myosin redistribution and causes retraction of the lamellipodial boundary. Actin protrusion at the boundary counters the retraction, and the balance of the protrusion and retraction shapes the lamellipodium. The model analysis shows that initiation of motility critically depends on three dimensionless parameter combinations, which represent myosin-dependent contractility, a characteristic viscosity-adhesion length, and a rate of actin protrusion. When the contractility is sufficiently strong, cells break symmetry and move steadily along either straight or circular trajectories, and the motile behavior is sensitive to conditions at the cell boundary. Scanning of a model parameter space shows that the contractile mechanism of motility supports robust cell turning in conditions where short viscosity-adhesion lengths and fast protrusion cause an accumulation of myosin in a small region at the cell rear, destabilizing the axial symmetry of a moving cell.

Original languageEnglish (US)
Article numbere1005862
JournalPLoS Computational Biology
Volume13
Issue number11
DOIs
StatePublished - Nov 1 2017

Fingerprint

Myosin
Myosins
myosin
Free Boundary
Actin
motility
adhesion
actin
Actins
contraction
Contractility
Motility
Adhesion
Retraction
Cell
symmetry
Contraction
viscosity
cells
Viscosity

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Modeling and Simulation
  • Ecology
  • Molecular Biology
  • Genetics
  • Cellular and Molecular Neuroscience
  • Computational Theory and Mathematics

Cite this

Nickaeen, M., Novak, I. L., Pulford, S., Rumack, A., Brandon, J., Slepchenko, B. M., & Mogilner, A. (2017). A free-boundary model of a motile cell explains turning behavior. PLoS Computational Biology, 13(11), [e1005862]. https://doi.org/10.1371/journal.pcbi.1005862

A free-boundary model of a motile cell explains turning behavior. / Nickaeen, Masoud; Novak, Igor L.; Pulford, Stephanie; Rumack, Aaron; Brandon, Jamie; Slepchenko, Boris M.; Mogilner, Alexander.

In: PLoS Computational Biology, Vol. 13, No. 11, e1005862, 01.11.2017.

Research output: Contribution to journalArticle

Nickaeen, M, Novak, IL, Pulford, S, Rumack, A, Brandon, J, Slepchenko, BM & Mogilner, A 2017, 'A free-boundary model of a motile cell explains turning behavior', PLoS Computational Biology, vol. 13, no. 11, e1005862. https://doi.org/10.1371/journal.pcbi.1005862
Nickaeen M, Novak IL, Pulford S, Rumack A, Brandon J, Slepchenko BM et al. A free-boundary model of a motile cell explains turning behavior. PLoS Computational Biology. 2017 Nov 1;13(11). e1005862. https://doi.org/10.1371/journal.pcbi.1005862
Nickaeen, Masoud ; Novak, Igor L. ; Pulford, Stephanie ; Rumack, Aaron ; Brandon, Jamie ; Slepchenko, Boris M. ; Mogilner, Alexander. / A free-boundary model of a motile cell explains turning behavior. In: PLoS Computational Biology. 2017 ; Vol. 13, No. 11.
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