Active stiffening of F-actin network dominated by structural transition of actin filaments into bundles

Shengmao Lin, Xinwei Han, Chi Pong Tsui, David Hui, Linxia Gu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)


The F-actin network demonstrates a two-order of magnitude increase in its modulus due to contractility; however, the mechanism for this active stiffening remains unclear. Two widely acknowledged hypotheses are that active stiffening of F-actin network is caused by (1) the nonlinear force-extension behavior of cross-linkers, and (2) the loading mode being switched from bending to stretching dominated regime. Direct evidence supporting either theory is lacking. Here we examined these hypotheses and showed that a reorganization of F-actin network from cross-linked filament state to bundled stress fiber state plays a key role on active stiffening of actin network. We demonstrated through computational models that the stretching of cross-linkers and molecular motors has less impact on the active stiffening, while it is more sensitive to cytoskeleton reorganization during the elasticity sensing. The proposed new mechanism involving the cytoskeletal remodeling was able to integrate discrete experimental observations and has the potential to advance our understanding of active sensing and responding of cells.
Original languageEnglish
Pages (from-to)377-381
Number of pages5
JournalComposites Part B: Engineering
Publication statusPublished - 1 May 2017


  • Active stiffening
  • Bundle
  • Computational biomechanics
  • Cross-linker
  • F-actin network
  • Molecular motor

ASJC Scopus subject areas

  • Ceramics and Composites
  • Mechanics of Materials
  • Mechanical Engineering
  • Industrial and Manufacturing Engineering

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