Integrin Cytoplasmic domain-Associated Protein-1 (ICAP-1) promotes migration of myoblasts and affects focal adhesions

J Cell Physiol. 2008 Feb;214(2):474-82. doi: 10.1002/jcp.21215.


Integrin Cytoplasmic domain-Associated Protein-1 (ICAP-1) binds specifically to the beta1 integrin subunit cytoplasmic domain. We observed that RNAi-induced knockdown of ICAP-1 reduced migration of C2C12 myoblasts on the beta1 integrin ligand laminin and that overexpression of ICAP-1 increased this migration. In contrast, migration on the beta3 integrin ligand vitronectin was not affected. ICAP-1 knockdown also greatly diminished migration of microvascular endothelial cells on collagen. The number of central focal adhesions in C2C12 cells on laminin was reduced by ICAP-1 knockdown and increased by ICAP-1 overexpression. Previously, we demonstrated that ICAP-1 binds to the ROCK-I kinase and translocates ROCK-I to the plasma membrane. We show here that the ROCK kinase inhibitor Y27362 reduces migration on laminin and causes a loss of central focal adhesions, similarly as ICAP-1 knockdown. ICAP-1 and ROCK were co-immune-precipitated from C2C12 cells, and in cells that overexpressed ICAP-1, YFP-ROCK was translocated to membrane ruffles. These results indicate that ICAP-1 regulates beta1 integrin-dependent cell migration by affecting the pattern of focal adhesion formation. This is likely due to ICAP-1-induced translocation of ROCK to beta1 integrin attachment sites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Antibodies, Monoclonal / metabolism
  • Cell Line
  • Cell Movement / physiology*
  • Chemotaxis / physiology*
  • DNA, Complementary
  • Embryo, Mammalian / cytology
  • Embryo, Mammalian / physiology
  • Escherichia coli / genetics
  • Fluorescent Antibody Technique, Indirect
  • Focal Adhesions / physiology*
  • Glutathione Transferase / metabolism
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Intracellular Signaling Peptides and Proteins / physiology*
  • Mice
  • Microscopy, Fluorescence
  • Myoblasts / physiology*
  • Phalloidine
  • Precipitin Tests
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Fusion Proteins / physiology
  • Transduction, Genetic
  • Transfection
  • Vinculin / metabolism
  • rho-Associated Kinases / metabolism


  • Actins
  • Antibodies, Monoclonal
  • DNA, Complementary
  • ICAP-1 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Recombinant Fusion Proteins
  • Vinculin
  • Phalloidine
  • Glutathione Transferase
  • Rock1 protein, mouse
  • rho-Associated Kinases