Membrane fission via transmembrane contact

Area of Science:

• Cell Biology
• Biophysics
• Biochemistry

Background:

• Organelle division often involves membrane wrapping, crucial for cellular organization.
• The mechanical impact of this extra membrane layer on division remains poorly understood.

Purpose of the Study:

• To investigate the mechanical effects of membrane wrapping on the division of double-membrane systems.
• To explore novel fission pathways induced by outer membrane wrapping.

Main Methods:

• Combined fluorescence microscopy and cryo-electron microscopy.
• Employed self-consistent field theory for theoretical analysis.
• Studied a simplified double-membrane tubular system.

Main Results:

• The outer membrane facilitates inner-tube fission via transient hemi-fusion.
• Identified alternative fission pathways with complex topologies.
• Characterized both leaky and leakless intermediates in the division process.

Conclusions:

• Membrane wrapping introduces stress-induced instabilities that alter division mechanics.
• The hemi-fusion pathway offers a new model for understanding organelle division.
• Theoretical and experimental findings predict key physiological events in double-membrane fission.