Adhesion of Active Cytoskeletal Vesicles.

Area of Science:

• Cell Biology
• Biophysics
• Synthetic Biology

Background:

• Cell adhesion is vital for biological processes like motility and sensing.
• Cellular shape adaptation plays a critical role in regulating adhesion.
• Existing models often lack the minimal components to study shape-adhesion dynamics.

Purpose of the Study:

• To investigate the role of shape remodeling in cell adhesion using a minimal experimental system.
• To understand how cytoskeletal dynamics influence adhesion to solid substrates.
• To determine the key factors enabling strong adhesion in dynamic cellular structures.

Main Methods:

• Assembled tunable cytoskeletal vesicles with controlled size, volume, and contractility.
• Utilized synthetic biology to create a minimal model for adhesion studies.
• Applied hypertonic osmotic pressure to induce vesicle deformation and analyzed membrane dynamics with molecular motors.

Main Results:

• Cytoskeletal vesicles require significant actin cortex remodeling for strong adhesion.
• Vesicle deformation under osmotic pressure generates dynamic excess membrane area.
• This generated membrane area contributes to adhesion energy, enabling attachment to rigid surfaces.
• Vesicles demonstrated adhesion comparable to cortex-free counterparts under strong forces.

Conclusions:

• Active shape remodeling, particularly actin cortex dynamics, is essential for robust cell adhesion.
• The ability to dynamically generate excess membrane area is a key mechanism for enhancing adhesion energy.
• A balance between deformability and adhesion strength is critical for cellular attachment to substrates.