EPIDERMAL GROWTH-FACTOR INDUCES PROTEIN-TYROSINE PHOSPHORYLATION AND ASSOCIATION OF P190 WITH RAS-GTP-ASE ACTIVATING PROTEIN IN CACO-2 CELLS

Epidermal growth factor (EGF) modulates several functions of human enterocytes. We report that this growth factor induces strong tyrosine phosphorylation stimulation of its receptor and several putative substrates of the receptor intrinsic kinase including c-erb B2 in proliferating human colon carcinoma cells (Caco-2). In addition EGF induces stable association of the GTP-ase activating protein of p21(ras) to the p190 protein and to a 62 mol.wt. tyrosine-phosphorylated protein. This association is probably consequent to EGF stimulation of protein tyrosine phosphorylation and could coordinate progression through cell cycle with polarity, cell-cell interactions and cell mobility.