Meta-Biol

• Pathways

The cytoplasmic domain of EGFR contains tyrosine, serine and threonine phosphorylation sites. Activation of ligand-responsive EGFR mutants through spontaneous or EGF-induced dimerization results in trans-autophosphorylation of 5 tyrosine residues (Y1016 i.e. Y992 in the mature protein, Y1092 i.e. Y1068 in the mature protein, Y1110 i.e. Y1086 in the mature protein,Y1172 i.e. Y1148 in the mature protein and Y1197 i.e. Y1173 in the mature protein), which enables constitutive receptor signaling as it provides specific binding sites for cytosolic target proteins involved in signal transduction (Zhang et al. 2006, Yun et al. 2007, Sordella et al. 2004, Lee et al. 2006). Tyrosine residue Y1069 i.e. Y1045 in the mature protein, involved in EGFR down-regulation, is usually phosphorylated in ligand-responsive EGFR mutants (Sordella et al. 2004, Lee et al. 2006). The exact phosphorylation pattern has not been examined for each mutant, but is assumed to closely follow, based on existing experimental evidence, the trans-autophosphorylation pattern of the wild-type EGFR.