Autophosphorylation sites on the epidermal growth factor receptor.
The epidermal growth factor (EGF) receptor is a tyrosine-specific protein kinase with autophosphorylating activity. A 300 amino acid-long region of the receptor's cytoplasmic domain matches (35-90% homology) sequences of transforming proteins from the src family and includes a putative nucleotide binding site. Several of the src transforming proteins have tyrosine kinase activity, but v-erb-B, which appears to be a truncated EGF receptor, is virtually identical to the receptor over this region and yet lacks detectable kinase activity. To locate possible acceptor sites in the v-erb-B protein, we have mapped these sites in the human EGF receptor. We report here that three tyrosine sites near the C-terminus are phosphorylated in vitro. In intact cells, we find that EGF stimulates phosphorylation of several sites, the tyrosine 14 residues from the C-terminus being modified the most extensively. The equivalent site is absent in the v-erb-B protein of avian erythroblastosis virus (AEV) and may influence tyrosine kinase activity.
D000595:Amino Acid Sequence; D004815:Epidermal Growth Factor / Q000502:physiology*; D066246:ErbB Receptors; D006801:Humans; D010766:Phosphorylation; D011956:Receptors, Cell Surface / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D011956:Receptors, Cell Surface; D014443:Tyrosine; D004815:Epidermal Growth Factor; D066246:ErbB Receptors