Isotropic actomyosin dynamics promote organization of the apical cell cortex in epithelial cells

J Cell Biol. 2014 Oct 13;207(1):107-21. doi: 10.1083/jcb.201402037.


Although cortical actin plays an important role in cellular mechanics and morphogenesis, there is surprisingly little information on cortex organization at the apical surface of cells. In this paper, we characterize organization and dynamics of microvilli (MV) and a previously unappreciated actomyosin network at the apical surface of Madin-Darby canine kidney cells. In contrast to short and static MV in confluent cells, the apical surfaces of nonconfluent epithelial cells (ECs) form highly dynamic protrusions, which are often oriented along the plane of the membrane. These dynamic MV exhibit complex and spatially correlated reorganization, which is dependent on myosin II activity. Surprisingly, myosin II is organized into an extensive network of filaments spanning the entire apical membrane in nonconfluent ECs. Dynamic MV, myosin filaments, and their associated actin filaments form an interconnected, prestressed network. Interestingly, this network regulates lateral mobility of apical membrane probes such as integrins or epidermal growth factor receptors, suggesting that coordinated actomyosin dynamics contributes to apical cell membrane organization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actomyosin / metabolism*
  • Animals
  • Cell Line, Tumor
  • Cell Membrane / physiology
  • Cell Polarity / physiology
  • Cell Proliferation
  • Dogs
  • Epithelial Cells / physiology*
  • Epithelium / metabolism
  • HeLa Cells
  • Hepatocyte Growth Factor / pharmacology
  • Heterocyclic Compounds, 4 or More Rings / pharmacology
  • Humans
  • Intercellular Junctions
  • MCF-7 Cells
  • Madin Darby Canine Kidney Cells
  • Microvilli / physiology*
  • Myosin Type II / antagonists & inhibitors
  • Myosin Type II / metabolism*


  • Heterocyclic Compounds, 4 or More Rings
  • blebbistatin
  • Hepatocyte Growth Factor
  • Actomyosin
  • Myosin Type II