Adhesive F-actin Waves: A Novel Integrin-Mediated Adhesion Complex Coupled to Ventral Actin Polymerization

PLoS One. 2011;6(11):e26631. doi: 10.1371/journal.pone.0026631. Epub 2011 Nov 1.

Abstract

At the leading lamellipodium of migrating cells, protrusion of an Arp2/3-nucleated actin network is coupled to formation of integrin-based adhesions, suggesting that Arp2/3-mediated actin polymerization and integrin-dependent adhesion may be mechanistically linked. Arp2/3 also mediates actin polymerization in structures distinct from the lamellipodium, in "ventral F-actin waves" that propagate as spots and wavefronts along the ventral plasma membrane. Here we show that integrins engage the extracellular matrix downstream of ventral F-actin waves in several mammalian cell lines as well as in primary mouse embryonic fibroblasts. These "adhesive F-actin waves" require a cycle of integrin engagement and disengagement to the extracellular matrix for their formation and propagation, and exhibit morphometry and a hierarchical assembly and disassembly mechanism distinct from other integrin-containing structures. After Arp2/3-mediated actin polymerization, zyxin and VASP are co-recruited to adhesive F-actin waves, followed by paxillin and vinculin, and finally talin and integrin. Adhesive F-actin waves thus represent a previously uncharacterized integrin-based adhesion complex associated with Arp2/3-mediated actin polymerization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Actin-Related Protein 2-3 Complex / metabolism
  • Actins / metabolism*
  • Animals
  • Bone Neoplasms / metabolism
  • Bone Neoplasms / pathology
  • Cell Adhesion*
  • Cells, Cultured
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / metabolism
  • Extracellular Matrix / metabolism
  • Female
  • Fibroblasts / cytology
  • Fibroblasts / metabolism
  • Humans
  • Integrins / metabolism*
  • Melanoma, Experimental / metabolism
  • Melanoma, Experimental / pathology
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Fluorescence
  • Osteosarcoma / metabolism
  • Osteosarcoma / pathology
  • Paxillin / metabolism
  • Talin / metabolism
  • Vinculin / metabolism*
  • Zyxin / metabolism*

Substances

  • Actin-Related Protein 2-3 Complex
  • Actins
  • Integrins
  • Paxillin
  • Talin
  • Zyxin
  • Vinculin