Self-organized stress patterns drive state transitions in actin cortices.

Journal Article (Journal Article)

Biological functions rely on ordered structures and intricately controlled collective dynamics. This order in living systems is typically established and sustained by continuous dissipation of energy. The emergence of collective patterns of motion is unique to nonequilibrium systems and is a manifestation of dynamic steady states. Mechanical resilience of animal cells is largely controlled by the actomyosin cortex. The cortex provides stability but is, at the same time, highly adaptable due to rapid turnover of its components. Dynamic functions involve regulated transitions between different steady states of the cortex. We find that model actomyosin cortices, constructed to maintain turnover, self-organize into distinct nonequilibrium steady states when we vary cross-link density. The feedback between actin network structure and organization of stress-generating myosin motors defines the symmetries of the dynamic steady states. A marginally cross-linked state displays divergence-free long-range flow patterns. Higher cross-link density causes structural symmetry breaking, resulting in a stationary converging flow pattern. We track the flow patterns in the model actomyosin cortices using fluorescent single-walled carbon nanotubes as novel probes. The self-organization of stress patterns we have observed in a model system can have direct implications for biological functions.

Full Text

Duke Authors

Cited Authors

  • Tan, TH; Malik-Garbi, M; Abu-Shah, E; Li, J; Sharma, A; MacKintosh, FC; Keren, K; Schmidt, CF; Fakhri, N

Published Date

  • June 6, 2018

Published In

Volume / Issue

  • 4 / 6

Start / End Page

  • eaar2847 -

PubMed ID

  • 29881775

Pubmed Central ID

  • PMC5990313

Electronic International Standard Serial Number (EISSN)

  • 2375-2548

International Standard Serial Number (ISSN)

  • 2375-2548

Digital Object Identifier (DOI)

  • 10.1126/sciadv.aar2847

Language

  • eng