Related Experiment Video
Updated: Jun 25, 2026

Analyses of Actin Dynamics, Clutch Coupling and Traction Force for Growth Cone Advance
Published on: October 21, 2021
Kinetic model for lamellipodal actin-integrin 'clutch' dynamics
Alice Macdonald1, A Rick Horwitz, Douglas A Lauffenburger
1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Abstract:
In migrating cells, with especial prominence in lamellipodial protrusions at the cell front, highly dynamic connections are formed between the actin cytoskeleton and the extracellular matrix through linkages of integrin adhesion receptors to actin filaments via complexes of cytosolic "connector" proteins. Myosin-mediated contractile forces strongly influence the dynamic behavior of these adhesion complexes, apparently in two counter-acting ways: negatively as the cell-generated forces enhance complex dissociation, and at the same time positively as force-induced signaling can lead to strengthening of the linkage complexes. The net balance arising from this dynamic interplay is challenging to ascertain a priori, rendering experimental studies difficult to interpret and molecular manipulations of cell and/or environment difficult to predict. We have constructed a kinetics-based model governing the dynamic behavior of this system. We obtained ranges of parameter value sets yielding behavior consistent with that observed experimentally for 3T3 cells and for CHO cells, respectively. Model simulations are able to produce results for the effects of paxillin mutations on the turnover rate of actin/integrin linkages in CHO cells, which are consistent with recent literature reports. Overall, although this current model is quite simple it provides a useful foundation for more detailed models extending upon it.
Related Concept Videos
Mechanism of Lamellipodia Formation
Actin Polymerization and Cell Motility
Actin cytoskeleton dynamics can produce pushing, pulling, and resistance forces that help the cell to migrate.
Formation of Higher-order Actin Filaments
The high-order actin networks...
Intracellular Signaling Affects Focal Adhesions
Some...
Actin Treadmilling
Activation of Integrins
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.

