Molecular Shape Solution for Mesoscopic Remodeling of Cellular Membranes

Area of Science:

• Cellular Biology
• Biophysics
• Materials Science

Background:

• Cellular membranes are dynamic structures composed of lipid bilayers that interact with various molecular species.
• The local shape of molecules influences the lipid bilayer, driving membrane transformations.
• Intracellular membrane dynamics rely on elastic transformations and molecular redistribution, influenced by chemical and curvature stress gradients.

Purpose of the Study:

• To explore the broader role of membrane curvature-composition coupling (CCC) in controlling membrane deformations beyond dynamic compositional heterogeneity.
• To investigate mesoscale membrane transformations in open, reservoir-governed systems, including budding, tubulation, fusion, and fission.
• To reveal molecular shape reshuffling as an independent deformation mode regulating intracellular membrane remodeling.

Main Methods:

• Theoretical analysis of molecular shape contributions to lipid bilayer elasticity.
• Investigation of mesoscale membrane transformations in open systems.
• Modeling of molecular shape reshuffling as a deformation mode.

Main Results:

• Identified membrane curvature-composition coupling (CCC) as a fundamental mechanism for controlling membrane deformations.
• Demonstrated that molecular shape reshuffling is an independent deformation mode with complex rheological properties.
• Showed this mode regulates local deformation elasticity and stationary elastic stress, impacting intracellular membrane remodeling.

Conclusions:

• Molecular shape reshuffling is a key regulator of intracellular membrane remodeling, influencing membrane elasticity and deformation.
• CCC plays a critical role in controlling diverse membrane processes, including budding, tubulation, fusion, and fission.
• Understanding these mechanisms provides insights into the fundamental principles governing cellular membrane organization and dynamics.