Fig. 1.

Molecular trafficking signals in EGFR. Schematic representation of the molecular signals in the intracellular part of the EGFR molecule (residues 648–1186) which have been implicated in the endocytic trafficking of the receptor. Sequence motifs and phosphorylation sites/motifs that are not conserved in other ErbBs are shown in “black”, conserved in ErbB2 only — in “blue”, conserved in ErbB3 and/or ErbB4 in addition to ErbB2 — in “red”, and in ErbB3/ErbB4 but not in ErbB2 — in “green”. There are ubiquitin-conjugation sites in the kinase domain that are either conserved in all ErbBs or present only in EGFR.