Adaptor protein Shc undergoes translocation and mediates up-regulation of the tyrosine kinase c-Src in EGF-stimulated A431 cells
Article first published online: 25 DEC 2001
Genes to Cells
Volume 5, Issue 9, pages 749–764, September 2000
How to Cite
Sato, K.-i., Kimoto, M., Kakumoto, M., Horiuchi, D., Iwasaki, T., Tokmakov, A. A. and Fukami, Y. (2000), Adaptor protein Shc undergoes translocation and mediates up-regulation of the tyrosine kinase c-Src in EGF-stimulated A431 cells. Genes to Cells, 5: 749–764. doi: 10.1046/j.1365-2443.2000.00358.x
- Issue published online: 25 DEC 2001
- Article first published online: 25 DEC 2001
- Cited By
Shc is the adaptor protein that exists in three isoforms, P46, P52 and P66, and acts as a bridge between activated cell surface receptors and downstream signalling molecules which act in extracellular signal-regulated cell events such as cell cycle progression. In our previous studies, Shc was shown to be a substrate of the tyrosine kinase c-Src in vitro and in vivo.
Using green fluorescent protein-fusion Shc (GFP-Shc), we have shown that following epidermal growth factor (EGF) stimulation of A431 cells, all Shc isoforms were rapidly recruited from the cytoplasm to the plasma membrane (within 5 min) and then redistributed to the cytoplasmic vesicle structures (in the next 10–20 min). Indirect immunofluorescent study demonstrated that all Shc isoforms co-localize with EGF receptor (EGFR) and activated c-Src in both plasma membranes and cytoplasmic vesicle structures. Our previous study has shown that EGF induces the indirect association of EGFR and c-Src and activation of c-Src in A431 cells. An immunoprecipitation study demonstrated that the EGFR–Src association and c-Src activation are augmented in cells expressing GFP-Shc P52 or P66, but not P46. In addition, P52 and P66, but not P46, are in association with EGFR-Src complex. We also found that EGFR and Shc can be dissociated from c-Src by the addition of a synthetic peptide that corresponds to the autophosphorylation site of c-Src. Interestingly, the peptide-induced dissociation of the complex was not affected by the tyrosine phosphorylation state of the peptide.
These results demonstrated a dynamic subcellular movement of Shc in response to EGF, and suggested a hitherto unknown scheme whereby Shc can work not only as a substrate of c-Src but also as a mediator of the EGF-induced activation of c-Src in an isoform-specific manner.