Hydrogen peroxide stimulates tyrosine phosphorylation of the insulin receptor and its tyrosine kinase activity in intact cells.
H-35 rat hepatoma cells were labelled with [32P]orthophosphate and their insulin receptors isolated on wheat germ agglutinin (WGA)-agarose and anti-(insulin receptor) serum. The incubation of these cells with 10 mM-H2O2 for 10 min increased the phosphorylation of both the serine and tyrosine residues of the beta subunit of the insulin receptor. Next, insulin receptors were purified on WGA-agarose from control and H2O2-treated H-35 cells and the purified fractions incubated with [gamma-32P]ATP and Mn2+. Phosphorylation of the beta subunit of insulin receptors obtained from H2O2-treated cells was 150% of that of control cells. The kinase activity of the WGA-purified receptor preparation obtained from H2O2-treated cells, as measured by phosphorylation of src-related synthetic peptide, was increased about 4-fold over control cells. These data suggest that in intact cell systems, H2O2 may increase the insulin receptor kinase activity by inducing phosphorylation of the beta subunit of insulin receptor.
Koshio
O
O
Institute for Diabetes Care and Research, Asahi Life Foundation, Tokyo, Japan.
Akanuma
Y
Y
Kasuga
M
M
D000596:Amino Acids / Q000032:analysis; D002460:Cell Line; D002474:Cell-Free System; D004591:Electrophoresis, Polyacrylamide Gel; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011972:Receptor, Insulin / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D013268:Stimulation, Chemical; D014443:Tyrosine / Q000378:metabolism*
D000596:Amino Acids; D007328:Insulin; D014443:Tyrosine; D006861:Hydrogen Peroxide; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin