Ligand-independent tyrosine phosphorylation of EGF receptor and the erbB-2/neu proto-oncogene product is induced by hyperosmotic shock.
Treatment of intact cells with media containing high concentrations of ionic and non-ionic solutes induced increased tyrosine phosphorylation of the epidermal growth factor (EGF) receptor and the protein product of the erbB-2/neu proto-oncogene. This self phosphorylation occurred in the absence of EGF or other growth factors. High concentrations of solutes did not activate phosphorylation of either isolated EGF receptor or EGF receptor solubilized by non-ionic detergents. No evidence for receptor dimerization was found in response to hyperosmotic shock. Since receptor dimers have been implicated in the EGF-induced activation of EGF receptor, hyperosmotic shock may activate EGF receptor by a different mechanism.
King
C R
CR
Rorer Biotechnology, King of Prussia, Pennsylvania 19406.
Borrello
I
I
Porter
L
L
Comoglio
P
P
Schlessinger
J
J
D002460:Cell Line; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D015151:Immunoblotting; D008024:Ligands / Q000378:metabolism*; D009994:Osmolar Concentration; D010766:Phosphorylation; D019000:Phosphotyrosine; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D018719:Erb-b2 Receptor Tyrosine Kinases; D012492:Salts / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000276:immunology / Q000378:metabolism*
D066246:ErbB Receptors; D008024:Ligands; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D012492:Salts; D012965:Sodium Chloride; D014443:Tyrosine; C000715470:MAS1 protein, human