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Updated: Jul 25, 2026
07:55
Analyzing Cell Surface Adhesion Remodeling in Response to Mechanical Tension Using Magnetic Beads
Published on: March 8, 2017
Integrin extension enables ultrasensitive regulation by cytoskeletal force
Jing Li1,2, Timothy A Springer3,2
1Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115.
Summary
Cytoskeletal force and adaptor binding are essential for ultrasensitive integrin activation. This switch-like mechanism relies on large conformational changes in integrins, coordinating cell adhesion with cytoskeletal dynamics.
Area of Science:
- Cell biology
- Biophysics
- Molecular dynamics
Background:
- Integrins are key cell surface receptors mediating cell adhesion.
- Integrin activation involves significant conformational changes, but the underlying mechanisms remain incompletely understood.
- Previous models of integrin activation were largely conceptual, lacking quantitative validation.
Purpose of the Study:
- To quantitatively compare models of integrin activation.
- To determine the roles of cytoskeletal adaptor binding and tensile force in integrin activation.
- To investigate the relationship between integrin conformational changes and activation mechanisms.
Main Methods:
- Utilized recent measurements of integrin ligand-binding affinity and free energy across conformational states.
- Analyzed the length scales associated with integrin conformational changes.
- Quantitatively compared different models of integrin activation.
Main Results:
- Found that both cytoskeletal adaptor binding and tensile force are required for ultrasensitive integrin activation.
- Demonstrated that force-induced, switch-like activation depends on large integrin extension (>130 Å).
- Showed that this extension matches the free-energy difference between inactive and active integrin states.
Conclusions:
- Integrin activation is regulated by a combination of adaptor binding and cytoskeletal force.
- The large conformational change in integrins is crucial for force-dependent, switch-like activation.
- These mechanisms enable cell adhesion to be coordinated with cytoskeletal dynamics through force in the low pN range.
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