Cloning and Mutational Analysis of the Shc-Phosphotyrosine Interaction/Phosphotyrosine-Binding Domain

The interaction between tyrosme phosphorylated growth-factor receptors and Src Homology 2 (SH2)-domain-containing proteins plays a critical role in growth-factor mediated signal transduction (1 ). The SH2 domains bind to receptors at phosphotyrosine residues with specificity dictated by ammo acids that lie carboxy-terminal to the phosphotyrosme. Identification of new SH2-domain proteins has provided great insight into signaling by growth-factor receptors. Our work has focused on cloning new SH2-domain proteins by screening bacterial-expression libraries with tyrosine phosphorylated epidermal growth-factor receptor (EGF-receptor). We call this method CORT for cloning of receptor targets and the proteins isolated Grbs for growth-factor receptor bound (2 –6 ) The clomng of Grb2 with this technique helped to elucldate the signaling pathway that leads from growth-factor receptors to Ras (7 ),