title: Molecular identification and properties of two cell surface receptors playing roles in mitogenesis and epigenesis.
abstract: Studies leading to the identification of cell surface receptor macromolecules which specifically recognize a hormone, epidermal growth factor (EGF), or gp70, the coat antigen of the C-type RNA tumor viruses, have been described. EGF receptors are internalized and processed by lysosomal protease action after interaction of receptor and EGF. Other hormones, which resemble EGF in their ability to trigger mitogenesis in cultured cells, interact with the EGF receptor in a yet to be defined, but probably indirect way, decreasing the number of EGF binding sites on the cell surface. The evidence at this point indicates that these hormones interact with EGF receptors through the communal utilization of a shared cellular mechanism for internalization of their receptors and the EGF receptors. The receptor for gp70 is not internalized in response to gp70 binding, but is instead shed into the medium by cultured cells. This receptor protein BPgp70 has now been isolated and purified to apparent homogeneity. Antibodies to BPgp70 completely block gp70 binding to cells at low concentration, indicating that BPgp70 is the physiological receptor for gp70.
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000302:isolation & purification* / Q000494:pharmacology; D002462:Cell Membrane / Q000032:analysis*; D004815:Epidermal Growth Factor / Q000302:isolation & purification* / Q000494:pharmacology; D066246:ErbB Receptors; D046911:Macromolecular Substances; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D010455:Peptides / Q000302:isolation & purification*; D011946:Receptors, Antigen / Q000302:isolation & purification* / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000302:isolation & purification*; D011971:Receptors, Immunologic / Q000302:isolation & purification*; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000494:pharmacology
chemical_list: D000956:Antigens, Viral; C026096:BPgp70; D046911:Macromolecular Substances; D008934:Mitogens; D010455:Peptides; D011946:Receptors, Antigen; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors