Article

The role of cell contraction and adhesion in dictyostelium motility.

Center for Theoretical Biological Physics, University of California, San Diego, La Jolla, California, USA.
Biophysical Journal (impact factor: 3.65). 07/2010; 99(1):50-8. DOI:10.1016/j.bpj.2010.03.057 pp.50-8
Source: PubMed

ABSTRACT The crawling motion of Dictyostelium discoideum on substrata involves a number of coordinated events including cell contractions and cell protrusions. The mechanical forces exerted on the substratum during these contractions have recently been quantified using traction force experiments. Based on the results from these experiments, we present a biomechanical model of the contraction phase of Dictyostelium discoideum motility with an emphasis on the adhesive properties of the cell-substratum contact. Our model assumes that the cell contracts at a constant rate and is bound to the substratum by adhesive bridges that are modeled as elastic springs. These bridges are established at a spatially uniform rate while detachment occurs at a spatially varying, load-dependent rate. Using Monte Carlo simulations and assuming a rigid substratum, we find that the cell speed depends only weakly on the detachment kinetics of the cell-substratum interface, in agreement with experimental data. By varying the parameters that control the adhesive and contractile properties of the cell, we are able to make testable predictions. We also extend our model to include a flexible substrate and show that our model is able to produce substratum deformations and force patterns that are quantitatively and qualitatively in agreement with experimental data.

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Keywords

adhesive properties
 
cell contractions
 
cell contracts
 
cell protrusions
 
cell speed
 
cell-substratum contact
 
cell-substratum interface
 
contractile properties
 
crawling motion
 
detachment kinetics
 
Dictyostelium discoideum motility
 
experimental data
 
force patterns
 
mechanical forces
 
Monte Carlo simulations
 
rigid substratum
 
spatially uniform rate
 
spatially varying
 
testable predictions
 
traction force experiments