Extra-cellular matrix proteins induce re-distribution of alpha-actinin-1 and alpha-actinin-4 in A431 cells

Cell Biol Int. 2007 Apr;31(4):360-5. doi: 10.1016/j.cellbi.2007.01.021. Epub 2007 Jan 21.

Abstract

Alpha-actinins are actin-binding proteins of non-muscle cells, which can participate in the regulation of transcription factor activity. We describe the distribution of alpha-actinin-1 and -4 depending on different actin cytoskeleton formed as a result of cell adhesion to extracellular matrix proteins, such as fibronectin and laminin 2/4. Immunofluorescent studies show a difference in the distribution of alpha-actinin and -4. Both isoforms localise along stress-fibres, but alpha-actinin-1 localises in the perinuclear region more abundantly than alpha-actinin-4. Western blot analysis demonstrated existence of truncated forms of both isoforms. Truncated alpha-actinin-1 appears in cells spread on fibronectin or laminin. Cell spreading also correlated with more tight association of alpha-actinin-4 with chromatin. Basing on our previous finding of an interaction of alpha-actinin-4 with p65 subunit of the NF-kappaB, we checked the possible influence of immobilised ligands on its redistribution in nuclear complexes containing p65. alpha-Actinin-4 seems to be present in some but not all nuclear complexes containing p65. Immobilised ligands may affect the interaction of alpha-actinin-4/p65 complexes with chromatin. The data suggest that adhesion to extra-cellular matrix may interfere in cellular reactions mediated by alpha-actinin-1 and -4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / metabolism*
  • Blotting, Western
  • Carcinoma, Squamous Cell / metabolism*
  • Cell Adhesion
  • Cytoplasm
  • Cytoskeleton / metabolism*
  • Fibronectins / metabolism*
  • Humans
  • Immunoprecipitation
  • Laminin / metabolism*
  • Microfilament Proteins / metabolism*
  • NF-kappa B / metabolism
  • Subcellular Fractions
  • Tumor Cells, Cultured

Substances

  • ACTN4 protein, human
  • Fibronectins
  • Laminin
  • Microfilament Proteins
  • NF-kappa B
  • Actinin