Different Paths to Src

Science's STKE  22 Feb 2000:
Vol. 2000, Issue 20, pp. tw7
DOI: 10.1126/stke.2000.20.tw7

The mechanism by which the nonreceptor tyrosine kinase Src is activated may determine how different cell surface receptors can generate specific effects through a common kinase. The epidermal growth factor receptor (EGFR) and the G-protein-linked β2-adrenergic receptor (βAR) both activate Src, yet different Src substrates become phosphorylated. Goi et al. show that the EGFR activates Src through the small GTP-binding proteins Ras and Ral, resulting in phosphorylation of the Src targets cortactin and Stat3. In contrast, the Ras-Ral pathway was not required for βAR to activate Src, and instead, the adaptor protein Shc was phosphorylated by Src. Just how substrate specificity is achieved remains to be determined, but the authors propose that the EGFR-Ral signaling pathway may activate a specific pool of Src that has access to specific substrates.

Goi, T., Shipitsin, M., Lu, Z., Foster, D.A., Klinz, S.G., and Feig, L.A. (2000) An EGF receptor/Ral-GTPase signaling cascade regulates c-Src activity and substrate specificity. EMBO J. 19: 623-630. [Abstract] [Full Text]