Activation of protein kinase C alpha inhibits insulin-stimulated tyrosine phosphorylation of insulin receptor substrate-1
| Autor: | Richard A. Roth, Janice E. Chin, Feng Liu |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
medicine.medical_specialty
DNA Complementary medicine.medical_treatment Blotting Western CHO Cells Transfection Phosphatidylinositol 3-Kinases chemistry.chemical_compound Endocrinology Insulin resistance Cricetinae Internal medicine Insulin receptor substrate medicine Animals Insulin Phosphorylation Phosphotyrosine Molecular Biology Immunosorbent Techniques Protein Kinase C Protein kinase C biology Tyrosine phosphorylation General Medicine Phosphoproteins medicine.disease Molecular biology IRS2 IRS1 Enzyme Activation Phosphotransferases (Alcohol Group Acceptor) Insulin receptor chemistry Insulin Receptor Substrate Proteins biology.protein Tetradecanoylphorbol Acetate Tyrosine Signal Transduction |
| Zdroj: | Molecular Endocrinology. 8:51-58 |
| ISSN: | 1944-9917 0888-8809 |
| Popis: | Chinese hamster ovary (CHO) cells were transfected with a cDNA encoding protein kinase C alpha (PKC) and a cell line (CHO-PKC alpha) expressing approximately 7-fold greater amounts of PKC as the parental cells were isolated. Activation of PKC by 12-O-tetradecanoylphorbol-13-acetate in the CHO-PKC alpha cells inhibited by approximately 75% the: 1) insulin-stimulated increase in antiphosphotyrosine precipitable phosphatidylinositol 3-kinase activity in these cells; 2) insulin-stimulated increase in PI 3-kinase activity associated with insulin receptor substrate-1; and 3) tyrosine phosphorylation of the endogenous substrate, insulin receptor substrate-1. In contrast, 12-O-tetradecanoylphorbol-13-acetate treatment did not inhibit any of these responses in the parental CHO cells. These results indicate that excessive PKC activity can interfere in a very early step in insulin receptor signaling and are consistent with the hypothesis that excessive PKC activity may contribute to some states of insulin resistance. |
| Databáze: | OpenAIRE |
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