Deep mutational analysis reveals functional trade-offs in the sequences of EGFR autophosphorylation sites.

摘要: Upon activation, the epidermal growth factor receptor (EGFR) phosphorylates tyrosine residues in its cytoplasmic tail, which triggers binding of Src homology 2 (SH2) and phosphotyrosine-binding (PTB) domains initiates downstream signaling. The sequences flanking (referred to as "phosphosites") must be compatible with phosphorylation by EGFR kinase domain recruitment adapter proteins, while minimizing that would reduce fidelity signal transmission. To understand how phosphosite encode these functions within a small set residues, we carried out high-throughput mutational analysis three tail. We used bacterial surface display peptides coupled deep sequencing monitor efficiency SH2 PTB proteins Grb2 Shc1, respectively. found phosphosites tail are restricted subset range can phosphorylated efficiently EGFR. Although efficient occur either acidic or large hydrophobic at -1 position respect tyrosine, generally excluded from this sequences. data suggest restriction results weaker but also disfavors kinases c-Src c-Abl. Our show EGFR-family achieve trade-off between off-pathway maintaining ability recruit diverse complement effectors required for pathway activation.