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Src family kinases are required for integrin but not PDGFR signal transduction
Author(s) -
Klinghoffer Richard A.,
Sachsenmaier Christoph,
Cooper Jonathan A.,
Soriano Philippe
Publication year - 1999
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/18.9.2459
Subject(s) - biology , signal transduction , kinase , proto oncogene tyrosine protein kinase src , microbiology and biotechnology , integrin , platelet derived growth factor receptor , integrin linked kinase , receptor protein tyrosine kinases , genetics , receptor , tyrosine kinase , protein kinase a , growth factor , cyclin dependent kinase 2
Src family kinases (SFKs) have been implicated as important regulators of ligand‐induced cellular responses including proliferation, survival, adhesion and migration. Analysis of SFK function has been impeded by extensive redundancy between family members. We have generated mouse embryos harboring functional null mutations of the ubiquitously expressed SFKs Src, Yes and Fyn. This triple mutation leads to severe developmental defects and lethality by E9.5. To elucidate the molecular mechanisms underlying this phenotype, SYF cells (deficient for Src, Yes and Fyn) were derived and tested for their ability to respond to growth factors or plating on extracellular matrix. Our studies reveal that while Src, Yes and Fyn are largely dispensable for platelet‐derived growth factor (PDGF)‐induced signaling, they are absolutely required to mediate specific functions regulated by extracellular matrix proteins. Fibronectin‐induced tyrosine phosphorylation of focal adhesion proteins, including the focal adhesion kinase FAK, was nearly eliminated in the absence of Src, Yes and Fyn. Furthermore, consistent with previous reports demonstrating the importance of FAK for cell migration, SYF cells displayed reduced motility in vitro . These results demonstrate that SFK activity is essential during embryogenesis and suggest that defects observed in SYF triple mutant embryos may be linked to deficiencies in signaling by extracellular matrix‐coupled receptors.