Abstract
Shc is an Src homology 2 (SH2) domain protein thought to be an important component of the signaling pathway leading from cell surface receptors to Ras. A new phosphotyrosine interaction (PI) domain (also known as the phosphotyrosine binding (PTB) domain) has been described in the amino terminus of Shc. The Shc PI domain binding specificity is dependent on residues lying amino-terminal to the phosphotyrosine rather than carboxyl-terminal as is seen with SH2 domains. We randomly mutagenized the Shc PTB/PI domain in an effort to identify residues in the domain crucial for interaction with phosphotyrosine-containing peptides. We then screened the mutants for binding to the tyrosine-phosphorylated carboxyl-terminal tail of the epidermal growth factor (EGF) receptor. Most striking were mutations that altered a phenylalanine residue in block 4 of the domain severely impairing PI domain function. This phenylalanine residue is conserved in all but one subfamily of PI domains that have been identified to date. Reconstitution of this phenylalanine mutation into full-length Shc created a protein unable to interact with the EGF receptor in living cells.
Highlights
Shc is an Src homology 2 (SH2) domain protein thought to be an important component of the signaling pathway leading from cell surface receptors to Ras
Shc becomes tyrosine-phosphorylated after cell activation with a large number of cytokines and growth factors [7,8,9] creating a high affinity binding site for the SH2 domain of Grb2
The binding of the phosphotyrosine interaction (PI) domain to phosphotyrosine-containing peptides differs from SH2 domain binding in that its specificity is determined by residues lying amino-terminal to the phosphotyrosine (6, 10 – 15)
Summary
Shc is an Src homology 2 (SH2) domain protein thought to be an important component of the signaling pathway leading from cell surface receptors to Ras. Shc becomes tyrosine-phosphorylated after cell activation with a large number of cytokines and growth factors [7,8,9] creating a high affinity binding site for the SH2 domain of Grb2. In an effort to understand residues in the PI domain important in mediating binding to phosphorylated peptides, we performed random mutagenesis of the Shc PI domain and screened the mutants for binding to tyrosine-phosphorylated EGF receptor.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
