| First Author | Meng F | Year | 1998 |
| Journal | EMBO J | Volume | 17 |
| Issue | 15 | Pages | 4391-403 |
| PubMed ID | 9687507 | Mgi Jnum | J:114192 |
| Mgi Id | MGI:3688479 | Doi | 10.1093/emboj/17.15.4391 |
| Citation | Meng F, et al. (1998) A beta 1 integrin signaling pathway involving Src-family kinases, Cbl and PI-3 kinase is required for macrophage spreading and migration. EMBO J 17(15):4391-403 |
| abstractText | We have used mutant macrophages which are deficient in expression of Src-family kinases to define an integrin signaling pathway that is required for macrophage adhesion and migration. Following ligation of surface integrins by fibronectin, the p120(c-cbl) (Cbl) protein rapidly becomes tyrosine phosphorylated and associated with the Src-family kinases Fgr and Lyn. In hck-/-fgr-/-lyn-/- triple mutant cells, which are defective in spreading on fibronectin-coated surfaces in vitro and show impaired migration in vivo, Cbl tyrosine phosphorylation is blocked, Cbl protein levels are low, adhesion-dependent translocation of Cbl to the membrane is impaired and Cbl-associated, membrane-localized phosphatidylinositol 3 (PI-3)-kinase activity is dramatically reduced. In contrast, adhesion-dependent activation of total cellular PI-3 kinase activity is normal in mutant cells, demonstrating that it is the membrane-associated fraction of PI-3 kinase which is most critical in regulating actin cytoskeletal rearrangements that lead to cell spreading. Treatment of wild-type cells with the Src-family-specific inhibitor PP1, Cbl antisense oligonucleotides or pharmacological inhibitors of PI-3 kinase blocks cell spreading on fibronectin surfaces. These data provide a molecular description for the role of Src-family kinases Hck, Fgr and Lyn in beta 1-integrin signal transduction in macrophages. |
