Cytoskeletal coherence requires myosin-IIA contractility

Yunfei Cai, Olivier Rossier, Nils C. Gauthier, Nicolas Biais, Marc Antoine Fardin, Xian Zhang, Lawrence W. Miller, Benoit Ladoux, Virginia W. Cornish, Michael P. Sheetz

Research output: Contribution to journalArticlepeer-review

161 Scopus citations


Maintaining a physical connection across cytoplasm is crucial for many biological processes such as matrix force generation, cell motility, cell shape and tissue development. However, in the absence of stress fibers, the coherent structure that transmits force across the cytoplasm is not understood. We find that nonmuscle myosin-II (NMII) contraction of cytoplasmic actin filaments establishes a coherent cytoskeletal network irrespective of the nature of adhesive contacts. When NMII activity is inhibited during cell spreading by Rho kinase inhibition, blebbistatin, caldesmon overexpression or NMIIA RNAi, the symmetric traction forces are lost and cell spreading persists, causing cytoplasm fragmentation by membrane tension that results in 'C' or dendritic shapes. Moreover, local inactivation of NMII by chromophore-assisted laser inactivation causes local loss of coherence. Actin filament polymerization is also required for cytoplasmic coherence, but microtubules and intermediate filaments are dispensable. Loss of cytoplasmic coherence is accompanied by loss of circumferential actin bundles. We suggest that NMIIA creates a coherent actin network through the formation of circumferential actin bundles that mechanically link elements of the peripheral actin cytoskeleton where much of the force is generated during spreading.

Original languageEnglish (US)
Pages (from-to)413-423
Number of pages11
JournalJournal of Cell Science
Issue number3
StatePublished - Feb 1 2010
Externally publishedYes


  • Actin
  • Cell spreading
  • Coherence
  • Fibroblast
  • Myosin-II
  • Traction force

ASJC Scopus subject areas

  • Cell Biology


Dive into the research topics of 'Cytoskeletal coherence requires myosin-IIA contractility'. Together they form a unique fingerprint.

Cite this