[Autophosphorylation of EGF receptors in the A431 cell line with an increased intracellular concentration of Ca(2+) ions].
The increase in the intracellular concentration of Ca2+ in A431 cells induced by the calcium ionophore A23187 leads to phosphorylation of epidermal growth factor (EGF) receptors at serine and/or threonine residues. This process is accompanied by the decrease in the level of EGF receptor autophosphorylation at tyrosine residues. Preincubation of cells in a A23187-containing medium in the presence of phorbol-12-myristoyl-13-acetate leads to a further decrease of the phosphotyrosine content in EGF receptors. At increased intracellular concentrations of Ca2+ preincubation of A431 cells with the protein kinase C inhibitor H-7 has no effect on the degree of EGF receptor autophosphorylation. Down-regulation of cellular protein kinase C does not change the A23187-induced effect either. The data obtained suggest that the decreased autophosphorylation of EGF receptors induced by Ca2+ is not due to the activation of cellular protein kinase C.
Kharitonenkov
A I
AI
Bulargina
T V
TV
D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D066246:ErbB Receptors / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000001:Calcimycin; D066246:ErbB Receptors; D011493:Protein Kinase C; D002118:Calcium
Avtofosforilirovanie retseptorov EFR v kletkakh linii A431 v usloviiakhpovyshennoĭ vnutrikletochnoĭ kontsentratsii ionov Ca(2+).