In order to clarify the physiological relevance of the interaction between She and adaptins, components of plasma membrane-coated pit adaptor complex AP2, we investigated the role of She in ligand-induced endocytosis of epidermal growth factor (EGF) receptors. In vitro peptide binding assay showed that alpha -adaptin bound to the wild-type peptide corresponding to amino acids 346-355 of Shc, RDLFDMKPFE, but not to the mutant peptide in which both phenylalanines at 349 and 354 were substituted for alanines (FA). Using adenovirus vectors carrying a herpes simplex virus epitope-tagged 52-kDa wild-type She and She FA, we examined the interaction between She, AP2, and EGF receptors in intact cells. Alpha-adaptin bound to wild-type She in an EGF-dependent manner, whereas EG;dependent association of alpha -adaptin with She FA was markedly reduced. In addition, EGF increased the amount of alpha -adaptin coprecipitated with EGF receptors in cells expressing wild-type She but not She FX. These results suggest that EGF stimulates Shc-AP2 complex formation and association of Shc-APa complexes with EGF receptors. Internalization assay showed that I-125-EGF internalization was reduced in cells overexpressing She FA. Immunofluorescence study showed that punctate staining along the plasma membrane border as web as punctate pattern characteristic of cytoplasmic vesicles near the plasma membrane was enhanced in cells expressing wild-type She. These results suggest, therefore, the implication of She in ligand-induced endocytosis of EGF receptors in intact cells.