3D pattern formation of a protein-membrane suspension

Area of Science:

• Biophysics
• Cell Biology
• Systems Biology

Background:

• Pattern-forming proteins regulate crucial cellular processes like division and polarity.
• These proteins typically interact with continuous 2D cell membranes to form patterns.
• The impact of membrane continuity on protein pattern formation remains poorly understood.

Purpose of the Study:

• To investigate how membrane discontinuity affects pattern formation by proteins.
• To explore the emergence of 3D patterns from fragmented lipid substrates.
• To characterize novel dynamical patterns and the underlying physical mechanisms.

Main Methods:

• Utilized the MinDE system, a model of pattern-forming membrane proteins.
• Dispersed the lipid substrate into submicrometer-sized diffusive liposomes.
• Systematically varied protein concentration, liposome size, and density.
• Employed simulations and linear stability analysis of a coarse-grained model.

Main Results:

• Generated extended 3D spatially organized patterns on fragmented liposomes, independent of membrane continuity.
• Observed novel 3D dynamical patterns, including traveling waves and spirals, at scales significantly larger than individual liposomes.
• Demonstrated that dispersed membrane properties rescale protein-membrane binding and diffusion rates.

Conclusions:

• Protein-membrane suspensions can generate complex 3D self-organization patterns.
• The MinDE system exhibits robust pattern-forming capabilities even on discontinuous substrates.
• Dispersed membranes offer a versatile platform for studying out-of-equilibrium self-organization beyond cellular contexts.