A combination of H2O2 and vanadate concomitantly stimulates protein tyrosine phosphorylation and polyphosphoinositide breakdown in different cell lines.
Treatment of four cell lines [rat hepatoma (Fao), murine muscle (BC3H-1), Chinese hamster ovary (CHO), and rat basophilic leukemia (RBL)] with a combination of 3 mM H2O2 and 1 mM sodium orthovanadate markedly stimulates protein tyrosine phosphorylation, which is accompanied by a dramatic increase (5-15-fold) in inositol phosphate (InsP) formation. H2O2/vanadate stimulate best formation of inositol triphosphate while their effects on the mono and di derivatives are more moderate. In the presence of 3 mM H2O2, both protein tyrosine phosphorylation and InsP formation are highly correlated and manifest an identical dose-response relationship for vanadate. Half-maximal and maximal effects are obtained at 30 and 100 microM, respectively. This stimulatory effect of H2O2/vanadate is not mimicked by other oxidants such as spermine, spermidine, KMnO4, and vitamin K3. In RBL cells, the kinetics of inositol triphosphate formation correlate with tyrosine phosphorylation of a 67-kDa protein, while tyrosine phosphorylation of a 55-kDa protein is closely correlated with both inositol monophosphate formation and serotonin secretion from these cells. Taken together, these results suggest a causal relationship between tyrosine phosphorylation triggered in a nonhormonal manner and polyphosphoinositide breakdown. Furthermore, these results implicate protein tyrosine phosphorylation in playing a role in the stimulus-secretion coupling in RBL cells.
Zick
Y
Y
Department of Chemical Immunology, Weizmann Institute of Science, Rehovot, Israel.
Sagi-Eisenberg
R
R
D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004357:Drug Synergism; D004789:Enzyme Activation; D005347:Fibroblasts / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015471:Leukemia, Basophilic, Acute / Q000473:pathology; D008114:Liver Neoplasms, Experimental / Q000473:pathology; D051379:Mice; D009132:Muscles / Q000166:cytology; D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D012701:Serotonin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014638:Vanadates / Q000494:pharmacology*
D018129:Phosphatidylinositol Phosphates; D010716:Phosphatidylinositols; D012701:Serotonin; D014638:Vanadates; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases