Actomyosin contractility is essential for biological force generation, and is well understood in highly ordered structures such as striated muscle. In vitro experiments have shown that non-sarcomeric bundles comprised only of F-actin and myosin thick filaments can also display contractile behavior , which cannot be described by standard muscle models. Here we investigate the microscopic symmetriesunderlying this process in large non-sarcomeric bundles with long actin filaments. We prove that contractile behavior requires non-identical motors that generate large enough forces to probe the nonlinear elastic behavior of F-actin. A simple disordered bundle model demonstrates a contraction mechanism based on these assumptions and predicts realistic bundle deformations. Recent experimental observations of F-actin buckling in in vitro contractile bundlessupport our model .
Actomyosin contractility is essential for biological force generation, and is well understood in URLanized structures such as striated muscle. Additionally, actomyosin bundles devoid of URLanization are known to contract both in vivo and in vitro , which cannot be described by standard muscle models. To narrow down the search for possible contraction mechanisms in these systems, we investigate their microscopic symmetries. We show that contractile behavior requires non-identical motors that generate large enough forces to probe the nonlinear elastic behavior of F-actin. This suggests a role for filament buckling in the contraction of these bundles, consistent with recent experimental results on reconstituted actomyosin bundles .
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highly ordered
URLanized
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In vitro experiments have shown that non-sarcomeric bundles comprised only of F-actin and myosin thick filaments can also display contractile behavior
Additionally, actomyosin bundles devoid of URLanization are known to contract both in vivo and in vitro
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Here we investigate the microscopic symmetriesunderlying this process in large non-sarcomeric bundles with long actin filaments. We prove
To narrow down the search for possible contraction mechanisms in these systems, we investigate their microscopic symmetries. We show
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A simple disordered bundle model demonstrates a contraction mechanism based on these assumptions and predicts realistic bundle deformations. Recent experimental observations of F-actin buckling in in vitro contractile bundlessupport our model
This suggests a role for filament buckling in the contraction of these bundles, consistent with recent experimental results on reconstituted actomyosin bundles