The pp60v-src tyrosine kinase desensitizes epidermal growth factor binding to 3T3 fibroblasts by two distinct protein kinase C-independent mechanisms.

摘要: Protein kinase C (Ca2+/phospholipid-dependent enzyme) is known to phosphorylate the epidermal growth factor receptor and reduce its affinity for factor. Transformation of 3T3 fibroblasts by oncogenic tyrosine pp60v-src accompanied an elevation cellular diacylglycerol partial activation protein (Wolfman, A., Wingrove, T. G., Blackshear, P. J., Macara, I. G. (1987) J. Biol. Chem. 262, 16546-16552). We therefore asked whether can down-modulate receptor. report that within 15 min activating temperature-sensitive pp60v-src, binding 125I-labeled cells falls at least 50%. Two distinct processes control down-modulation pp60v-src. The first rapid transient, while second requires synthesis persists long after inactivation Surprisingly, both mechanisms seem be C-independent. Both operate decreasing ligand.