Fiber plucking by molecular motors yields large emergent contractility in stiff biopolymer networks
arXiv:1805.04624
Abstract
The mechanical properties of the cell depend crucially on the tension of its cytoskeleton, a biopolymer network that is put under stress by active motor proteins. While the fibrous nature of the network is known to strongly affect the transmission of these forces to the cellular scale, our understanding of this process remains incomplete. Here we investigate the transmission of forces through the network at the individual filament level, and show that active forces can be geometrically amplified as a transverse motor-generated force force "plucks" the fiber and induces a nonlinear tension. In stiff and densely connnected networks, this tension results in large network-wide tensile stresses that far exceed the expectation drawn from a linear elastic theory. This amplification mechanism competes with a recently characterized network-level amplification due to fiber buckling, suggesting that that fiber networks provide several distinct pathways for living systems to amplify their molecular forces.
arXiv comment6 pages, 4 figures
References in corpus (10)
- Modeling semiflexible polymer networks
- Generic theory of active polar gels: a paradigm for cytoskeletal dynamics
- Criticality and isostaticity in fiber networks
- Long Range Force Transmission in Fibrous Matrices Enabled by Tension-Driven Alignment of Fibers
- Cell contraction induces long-ranged stress stiffening in the extracellular matrix
- Fiber networks amplify active stress
- Nonlinear elasticity of the extracellular matrix fibers facilitates efficient inter-cellular mechanical communication
- Entropy Production Rate is Maximized in Non-Contractile Actomyosin
- A Model for Compression-Weakening Materials and the Elastic Fields due to Contractile Cells
- Scaling laws for the response of nonlinear elastic media with implications for cell mechanics