Cell Biology

Cytoskeleton and Substrate Stiffness

Science Signaling  16 Dec 2008:
Vol. 1, Issue 50, pp. ec431
DOI: 10.1126/scisignal.150ec431

Substrate stiffness is sensed by cells and affects motility, morphology, and cell fate. Linking molecules between filamentous (F)-actin and the extracellular substrate are thought to act as “clutches” that transmit traction forces and slow F-actin retrograde flow. Chan and Odde (see the Perspective by Aratyn-Schaus and Gardel) now consider the effect of substrate stiffness by modeling both the clutch molecules and the substrate as Hookean springs. The model suggests that substrate stiffness–dependent changes in clutch dynamics result in higher retrograde flow rates with lower traction forces on stiff substrates and lower retrograde flow rates on soft substrates. As predicted, in embryonic chick forebrain neurons, a switch in F-actin dynamics was observed at an elastic modulus of about 1 kilopascal.

C. E. Chan, D. J. Odde, Traction dynamics of filopodia on compliant substrates. Science 322, 1687–1691 (2008). [Abstract] [Full Text]

Y. Aratyn-Schaus, M. L. Gardel, Clutch dynamics. Science 322, 1646–1647 (2008). [Summary] [Full Text]