title: Integrin Cytoplasmic domain-Associated Protein-1 (ICAP-1) promotes migration of myoblasts and affects focal adhesions.
abstract: 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.
authors.affiliation: Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Belén
authors.initials: B
authors.lastname: Alvarez
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Stroeken
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Edel
authors.forename: Ed
authors.initials: E
authors.lastname: Roos
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D018076:DNA, Complementary; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D022001:Focal Adhesions / Q000502:physiology*; D005982:Glutathione Transferase / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008856:Microscopy, Fluorescence; D032446:Myoblasts / Q000502:physiology*; D010590:Phalloidine; D011233:Precipitin Tests; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology; D014161:Transduction, Genetic; D014162:Transfection; D016596:Vinculin / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism
chemical_list: D000199:Actins; D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; C512603:ICAP-1 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D011993:Recombinant Fusion Proteins; D016596:Vinculin; D010590:Phalloidine; D005982:Glutathione Transferase; C515854:Rock1 protein, mouse; D054460:rho-Associated Kinases