Condensate-mediated shape transformations of cellular membranes by capillary forces

Area of Science:

• Cell biology
• Biophysics
• Biochemistry

Background:

• Phase-separated biomolecular condensates organize intracellular environments.
• Condensates influence membrane-bound organelles via capillary forces.
• Understanding condensate-membrane interactions is crucial for cellular organization.

Purpose of the Study:

• To investigate how biomolecular condensates mediate membrane shape transformations.
• To characterize the relationship between interfacial tension and membrane morphologies.
• To explore the dynamics and energy landscapes of condensate-induced membrane shape changes.

Main Methods:

• In planta live-cell imaging of plant cells.
• In vitro reconstitution system with tunable interfacial tension.
• Computer simulations using an elastic membrane model.

Main Results:

• Identified three membrane morphologies at condensate interfaces: tubes, sheets, and cups.
• High interfacial tension favors sheet formation; lower tension favors tubes and cups.
• Observed hysteresis in shape transitions, specifically tube-to-cup, dependent on membrane history.

Conclusions:

• Condensate surface properties dynamically control membrane shape.
• Temporal modulation of condensate tension can drive specific morphogenesis, like vacuolar bulb formation.
• The interplay between condensates and membranes is a general mechanism for intracellular organization.