Phorbol esters stimulate phosphatidylinositol 3,4,5-trisphosphate production in 3T3-L1 adipocytes: implications for stimulation of glucose transport
| Autor: | Kenneth Siddle, Barbara T. Navé, Peter R. Shepherd |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
medicine.medical_specialty
Morpholines medicine.medical_treatment Blotting Western Stimulation Biology Phosphatidylinositols Biochemistry Wortmannin Insulin Antagonists Mice Phosphatidylinositol 3-Kinases chemistry.chemical_compound Phosphatidylinositol Phosphates Internal medicine Adipocytes medicine Animals Insulin LY294002 Enzyme Inhibitors Phosphotyrosine Molecular Biology Phosphatidylinositol (3 4 5)-trisphosphate Glucose transporter Biological Transport 3T3-L1 3T3 Cells Cell Biology Precipitin Tests Androstadienes Phosphotransferases (Alcohol Group Acceptor) Glucose Endocrinology chemistry Chromones Phorbol Tetradecanoylphorbol Acetate Research Article |
| Zdroj: | Biochemical Journal. 318:203-205 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj3180203 |
| Popis: | The effects of insulin and phorbol 12-myristate 13-acetate (PMA) on the levels of cellular phosphoinositides were investigated in 3T3-L1 adipocytes. Stimulation for 4 min with PMA (1 µ M) or insulin (10 nM) increased levels of PtdIns(3,4,5) P 3 approx. 2-fold and 6-fold respectively. PMA also had a small effect on the cellular levels of PtdIns4 P , whereas insulin had no effect on PtdIns4 P levels; levels of PtdIns(4,5) P 2 and PtdIns3 P were not significantly affected by either agent. Insulin increased the levels of the p85α subunit of phosphoinositide (PI) 3-kinase associated with membranes, whereas PMA decreased levels of membrane-associated p85α. PMA did not increase PI 3-kinase activity in anti-phosphotyrosine or anti-p85 immunoprecipitates. The stimulation of glucose transport by insulin or PMA was blocked by 100 nM wortmannin or 10 ng/ml LY294002, indicating that PI 3-kinase is essential for stimulation by both agents. In summary, these results demonstrate: (1) that PMA and insulin stimulate PtdIns(3,4,5) P 3 production by distinct mechanisms in 3T3-L1 adipocytes, and (2) that stimulation of PtdIns(3,4,5) P 3 production by PMA is likely to be important in signalling pathways leading from PMA stimulation to end-point responses such as glucose transport. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|