Dystrophin Dp71f associates with the beta1-integrin adhesion complex to modulate PC12 cell adhesion

J Mol Biol. 2006 Oct 6;362(5):954-65. doi: 10.1016/j.jmb.2006.07.075. Epub 2006 Aug 1.

Abstract

Dystrophin Dp71 is the main product of the Duchenne muscular dystrophy gene in the brain; however, its function is unknown. To study the role of Dp71 in neuronal cells, we previously generated by antisense treatment PC12 neuronal cell clones with decreased Dp71 expression (antisense-Dp71 cells). PC12 cells express two different splicing isoforms of Dp71, a cytoplasmic variant called Dp71f and a nuclear isoform called Dp71d. We previously reported that antisense-Dp71 cells display deficient adhesion to substrate and reduced immunostaining of beta1-integrin in the cell area contacting the substrate. In this study, we isolated additional antisense-Dp71 clones to analyze in detail the potential involvement of Dp71f isoform with the beta1-integrin adhesion system of PC12 cells. Immunofluorescence analyses as well as immunoprecipitation assays demonstrated that the PC12 cell beta1-integrin adhesion complex is composed of beta1-integrin, talin, paxillin, alpha-actinin, FAK and actin. In addition, our results showed that Dp71f associates with most of the beta1-integrin complex components (beta1-integrin, FAK, alpha-actinin, talin and actin). In the antisense-Dp71 cells, the deficiency of Dp71 provokes a significant reduction of the beta1-integrin adhesion complex and, consequently, the deficient adhesion of these cells to laminin. In vitro binding experiments confirmed the interaction of Dp71f with FAK and beta1-integrin. Our data indicate that Dp71f is a structural component of the beta1-integrin adhesion complex of PC12 cells that modulates PC12 cell adhesion by conferring proper complex assembly and/or maintenance.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actinin / metabolism
  • Animals
  • Cell Adhesion / physiology*
  • Cell Culture Techniques
  • Cell Line, Tumor
  • Dystrophin / genetics
  • Dystrophin / metabolism*
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism
  • Glutathione Transferase / metabolism
  • Integrin beta1 / metabolism
  • Laminin / metabolism
  • Models, Biological
  • Neurons / physiology*
  • PC12 Cells
  • Protein Binding
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Rats
  • Recombinant Proteins / metabolism
  • Talin / metabolism

Substances

  • Dystrophin
  • Integrin beta1
  • Laminin
  • Protein Isoforms
  • Recombinant Proteins
  • Talin
  • Actinin
  • Glutathione Transferase
  • Focal Adhesion Protein-Tyrosine Kinases