Research Website

https://engineering.purdue.edu/mct/

Keywords

Simulation, actin, myosin, cytoskeleton, buckling

Presentation Type

Event

Research Abstract

Actomyosin cortex, a thin network underlying cell membrane, is known to generate a large portion of tensile forces required for various cellular processes. Recently, theoretical studies predicted that buckling of actin filaments breaks symmetry between tensile and compressive forces developed by myosin motors, resulting in tensile stress at a network level. However, the significance of the filament buckling of the cortex has yet to be demonstrated either computationally or experimentally. Here, buckling-dependent stress generation of the cortex-like actomyosin network was investigated using an agent-based computational model consisting of actin filaments, actin cross-linking proteins (ACPs), and molecular motors. First, a wide parametric space of filament length and the densities of ACP and motors was explored. It was found that the importance of the buckling varies depending on conditions; with higher ACP/motor densities and longer actin filaments, symmetry breaking induced by buckling is more severe. Using the data collected from the model, it was explained why the buckling is more likely to occur under such conditions. In addition, by analyzing temporal evolutions of filament behaviors, it was showed that some of the buckled filaments become subjected to tensile forces in a later stage, which was not predicted by the theoretical models.

Session Track

Biotechnology and Biomedical Engineering

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Aug 6th, 12:00 AM

Buckling-driven Force Generation of Cell Cortex

Actomyosin cortex, a thin network underlying cell membrane, is known to generate a large portion of tensile forces required for various cellular processes. Recently, theoretical studies predicted that buckling of actin filaments breaks symmetry between tensile and compressive forces developed by myosin motors, resulting in tensile stress at a network level. However, the significance of the filament buckling of the cortex has yet to be demonstrated either computationally or experimentally. Here, buckling-dependent stress generation of the cortex-like actomyosin network was investigated using an agent-based computational model consisting of actin filaments, actin cross-linking proteins (ACPs), and molecular motors. First, a wide parametric space of filament length and the densities of ACP and motors was explored. It was found that the importance of the buckling varies depending on conditions; with higher ACP/motor densities and longer actin filaments, symmetry breaking induced by buckling is more severe. Using the data collected from the model, it was explained why the buckling is more likely to occur under such conditions. In addition, by analyzing temporal evolutions of filament behaviors, it was showed that some of the buckled filaments become subjected to tensile forces in a later stage, which was not predicted by the theoretical models.

http://docs.lib.purdue.edu/surf/2015/presentations/155