A bistable model of cell polarity
Matteo Semplice1, Andrea Veglio, Giovanni Naldi
1Department of Physics and Mathematics, Università dell'Insubria, Como, Italy.
Plos One
|March 3, 2012
Summary
Ultrasensitivity and feedback loops can create bistability in cell membranes, leading to spatial separation and cell polarization. This mechanism explains fundamental biological processes like cell differentiation and migration.
Area of Science:
- Cell Biology
- Biophysics
- Systems Biology
Background:
- Ultrasensitivity is known to create bistable switches in biological systems.
- The role of ultrasensitivity and feedback in spatial systems, like cell membranes, for inducing bistability and phase separation is less recognized.
Purpose of the Study:
- To propose that bistability in ultrasensitive signaling pathways within a diffusive environment is a fundamental mechanism for cell membrane polarization.
- To present a model for cell membrane polarization based on coupled membrane diffusion and bistable enzymatic dynamics.
Main Methods:
- Development of a simple, solvable model.
- Coupling of membrane diffusion with bistable enzymatic dynamics.
- Analysis of symmetry-breaking events.
Main Results:
- The model demonstrates how ultrasensitivity and feedback loops can lead to bistability and spatial separation in signaling pathways.
- The proposed mechanism successfully reproduces various symmetry-breaking events observed in biological systems.
- The model provides a basic framework for understanding cell membrane polarization.
Conclusions:
- Bistability arising from ultrasensitive signaling pathways in a diffusive environment is a key mechanism for cell membrane polarization.
- This mechanism underlies fundamental cellular processes including differentiation, proliferation, migration, and morphogenesis.
- The model offers insights into diverse phenomena such as eukaryotic directional sensing and yeast polarization.
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