Structural, mechanical, and dynamical variability of the actin cortex in living cells

Area of Science:

• Cell Biology
• Biophysics
• Cytoskeleton Dynamics

Background:

• The actin cortex, an actin-based network lining the plasma membrane, is vital for eukaryotic cell mechanics and function.
• Studying the structural dynamics of the actin cortex at high resolution in living cells has been a significant challenge.

Purpose of the Study:

• To investigate the structural dynamics and mechanical properties of the actin cortex in living cells at high resolution.
• To characterize the different arrangements of cortical actin filaments and their impact on network behavior.

Main Methods:

• Utilized atomic force microscopy (AFM) for time-lapse imaging of living cells.
• Employed AFM for high-resolution mechanical mapping of the actin cortex.
• Analyzed the spatial organization and connectivity of actin filaments.

Main Results:

• Identified distinct actin filament arrangements, including parallel bundles and tight meshworks.
• Observed that mixed architectures lead to specific network connectivity and mechanical responses.
• Demonstrated marked differences in the dynamic behavior of various cortical actin structures.

Conclusions:

• The structural organization of the actin cortex is highly variable and influences its mechanical properties.
• High-resolution imaging and mechanical mapping reveal the dynamic nature of cortical actin networks.
• Understanding these dynamics is crucial for comprehending cell mechanics and function.