Contractile ring composition dictates kinetics of in silico contractility
Daniel B Cortes1, Paul S Maddox1, Francois J Nédéléç2
1Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Biophysical Journal
|December 21, 2022
Summary
Cytokinetic ring constriction depends on component levels. Dynamic changes in F-actin and myosin II abundance, not constant amounts, drive realistic cell division kinetics in computational models.
Area of Science:
- Cell Biology
- Biophysics
- Computational Biology
Background:
- Cytokinetic ring constriction is crucial for cell division.
- The impact of dynamic changes in contractile ring component abundance on constriction kinetics is understudied.
- Computational models often assume constant component levels, which may not reflect biological reality.
Purpose of the Study:
- To investigate how dynamic changes in contractile ring component abundance affect constriction kinetics.
- To test the influence of measured F-actin, non-muscle myosin II, septin, and anillin dynamics on ring constriction.
- To develop and utilize a computational model incorporating experimentally determined component abundance changes.
Main Methods:
- Measured F-actin, non-muscle myosin II, septin, and anillin abundances during Caenorhabditis elegans zygotic mitosis.
- Utilized a custom microfluidic device for precise cell positioning and light sheet illumination.
- Developed a three-dimensional agent-based model of a membrane-associated contractile ring, incorporating measured component dynamics.
Main Results:
- Simulations with constant component amounts yielded biologically unrealistic constriction kinetics.
- Incorporating measured dynamic changes in component abundances resulted in realistic constriction kinetics.
- The model demonstrated higher sensitivity to changes in motor (myosin II) and filament (actin) amounts compared to crosslinkers (anillin) and tethers (septins).
Conclusions:
- Dynamic adjustment of contractile ring composition is critical for regulating actomyosin contraction kinetics.
- Computational models must account for changing component abundances to accurately simulate cell division.
- Findings emphasize the importance of network composition dynamics in actomyosin-based cellular processes.
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