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Cell protrusions and contractions generate long-range membrane tension propagation
Henry De Belly1, Shannon Yan2, Hudson Borja da Rocha3
1Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA.
Cell
|June 13, 2023
Summary
Cellular membrane tension rapidly propagates globally when engaging the actin cortex via protrusions or contractions. This clarifies how cells transmit mechanical forces for physiological processes.
Area of Science:
- Cellular mechanics
- Biophysics
- Cell biology
Background:
- Membrane tension integrates cell physiology and is crucial for cell polarity and migration.
- Previous studies conflict on whether cell membranes support or resist tension propagation.
- Discrepancies may arise from using exogenous forces that don't mimic endogenous cellular forces.
Purpose of the Study:
- To investigate the mechanisms of membrane tension propagation within cells.
- To differentiate the effects of endogenous versus exogenous forces on tension transmission.
- To elucidate how cellular forces influence global membrane tension dynamics.
Main Methods:
- Utilized optogenetics to precisely control localized actin-based protrusions and actomyosin contractions.
- Employed dual-trap optical tweezers to monitor membrane tension propagation in real-time.
- Developed a unifying mechanical model to explain observed tension propagation.
Main Results:
- Actin-driven protrusions and actomyosin contractions rapidly induced global membrane tension propagation.
- Forces applied solely to cell membranes did not result in significant tension propagation.
- Engaging the actin cortex is critical for robust, long-range membrane tension transmission.
Conclusions:
- Cellular forces engaging the actin cortex drive rapid and global membrane tension propagation.
- Membrane tension transmission is mediated by long-range membrane flows linked to the actin cytoskeleton.
- This finding reconciles previous conflicting observations regarding membrane tension propagation.
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