Integrin cytoplasmic domain-associated protein-1 (ICAP-1) promotes migration of myoblasts and affects focal adhesions

• Published in: Journal of cellular physiology 2008-02, Vol.214 (2), p.474-482
• Main Authors: Alvarez, Belén, Stroeken, Peter J.M., Edel, Michael J., Roos, Ed
• Format: Article
• Language: English
• Subjects: 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; rho-Associated Kinases - metabolism; Transduction, Genetic; Transfection; Vinculin - metabolism
• ISSN: 0021-9541; 1097-4652
• DOI: 10.1002/jcp.21215

Integrin Cytoplasmic domain‐Associated Protein‐1 (ICAP‐1) binds specifically to the β1 integrin subunit cytoplasmic domain. We observed that RNAi‐induced knockdown of ICAP‐1 reduced migration of C2C12 myoblasts on the β1 integrin ligand laminin and that overexpression of ICAP‐1 increased this migration. In contrast, migration on the β3 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 β1 integrin‐dependent cell migration by affecting the pattern of focal adhesion formation. This is likely due to ICAP‐1‐induced translocation of ROCK to β1 integrin attachment sites. J. Cell. Physiol. 214: 474–482, 2008. © 2007 Wiley‐Liss, Inc.