Biosynthesis of the epidermal growth factor receptor: post-translational glycosylation-independent acquisition of tyrosine kinase autophosphorylation activity.
We previously showed that the epidermal growth factor (EGF) receptor in human A431 epidermoid carcinoma cells undergoes a slow post-translational modification whereby it acquires (t1/2 = 30-40 min) EGF binding capacity (Slieker, L.J., et. al. (1986) J. Biol. Chem., 261, 15233-15241). This activation occurs in the endoplasmic reticulum and requires core N-linked glycosylation. By employing both anti-EGF receptor and anti-phosphotyrosine antibodies to immunoprecipitate receptor pulse-labeled with [35S]methionine, we demonstrate here that the EGF receptor also acquires tyrosine kinase autophosphorylation activity post-translationally (t1/2 = 10-15 min). The acquisition of tyrosine kinase activity is independent of the acquisition of EGF binding capacity, since it precedes the latter process and does not require N-linked glycosylation.
Slieker
L J
LJ
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Martensen
T M
TM
Lane
M D
MD
D000255:Adenosine Triphosphate / Q000378:metabolism; D000906:Antibodies; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D006031:Glycosylation; D006801:Humans; D008970:Molecular Weight; D010766:Phosphorylation; D019000:Phosphotyrosine; D011499:Protein Processing, Post-Translational; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D014415:Tunicamycin / Q000494:pharmacology; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D000906:Antibodies; D014415:Tunicamycin; D019000:Phosphotyrosine; D014443:Tyrosine; D000255:Adenosine Triphosphate; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases