Actomyosin contraction, aggregation and traveling waves in a treadmilling actin array
1Courant Inst. of Math. Sciences, New York University, 251 Mercer St, New York, NY 10012.
Physica D. Nonlinear Phenomena
|March 19, 2016
Summary
This study models actomyosin dynamics, revealing that slow actin treadmilling causes aggregation, while faster treadmilling creates waves. Increased actomyosin turnover promotes contraction by preventing aggregation.
Area of Science:
- Biophysics
- Cell Biology
- Theoretical Biology
Background:
- Actomyosin bundles and rings are crucial for cellular processes like contraction and division.
- Understanding their dynamic behavior under strong crosslinking is essential for cell mechanics.
Purpose of the Study:
- To develop a continuum model for dynamic actomyosin bundles/rings.
- To investigate the role of actin treadmilling in actomyosin organization and contraction.
- To explore strategies for enhancing cellular contraction.
Main Methods:
- Utilized perturbation theory to derive a continuum model.
- Employed linear stability analysis.
- Performed numerical solutions of the model equations.
Main Results:
- Slow actin treadmilling leads to equidistant actin and myosin aggregation.
- Significant treadmilling results in evenly distributed actin filaments of one polarity and shock waves for the opposite polarity.
- Myosin forms sharp peaks on actin waves, and aggregation reduces contractile stress.
Conclusions:
- Actomyosin aggregation diminishes contractile stress; higher contraction is achieved by upregulating actomyosin turnover.
- Increased turnover destabilizes complex patterns, favoring homogeneous distributions and sustained contraction.
- The model provides insights into experimental observations of actomyosin dynamics.
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