Biosynthesis of the epidermal growth factor receptor: post-translational glycosylation-independent acquisition of tyrosine kinase autophosphorylation activity |
| |
Authors: | L J Slieker T M Martensen M D Lane |
| |
Institution: | Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205. |
| |
Abstract: | 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. |
| |
Keywords: | |
|
|