Differential phosphorylation of the docking protein Gab1 by c-Src and the hepatocyte growth factor receptor regulates different aspects of cell functions.
Oncogene
; 29(5): 698-710, 2010 Feb 04.
Article
em En
| MEDLINE
| ID: mdl-19881549
ABSTRACT
The docking protein Grb2-associated binder1 (Gab1) has a central role in the integration of the growth-factor signaling. In this study, we aimed to examine the significance of Src-mediated Gab1 phosphorylation in the hepatocyte growth factor (HGF) signaling. Using both mutagenesis and mass spectrometry approaches, Y242, Y259, Y317, Y373 and Y627 of Gab1 were identified to be phosphorylated by c-Src. It is interesting to note that the binding of the tyrosine phosphatase SHP2 to the Y627 antagonized the effect of c-Src on the phosphorylation of the other four tyrosine residues. Moreover, the tyrosine residues predominantly phosphorylated by c-Src were different from those predominantly phosphorylated by the HGF receptor. Gab1 overexpression potentiated both mitogenic and motogenic activities of HGF. However, a Gab1 mutant with substitutions of the Src phosphorylation sites (Y242, Y259, Y317 and Y373) failed to promote HGF-induced DNA synthesis, but retained its ability to facilitate HGF-induced chemotaxis. Taken together, our results not only suggest that the phosphorylation of Gab1 by c-Src is important for HGF-induced DNA synthesis, but also provide an example to illustrate how a docking protein (for example, Gab1) is differentially phosphorylated by c-Src and a receptor tyrosine kinase to emanate full spectrum of signals to the downstream.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Tirosina Quinases
/
Transdução de Sinais
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Proteínas Proto-Oncogênicas
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Proteínas Proto-Oncogênicas c-met
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Proteínas Adaptadoras de Transdução de Sinal
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article