Involvement of phosphoinositide 3-kinase in insulin stimulation of MAP-kinase and phosphorylation of protein kinase-B in human skeletal muscle: implications for glucose metabolism
| Autor: | Christopher G. Proud, H. Wallberg-Henriksson, Jorge Rincon, E.J. Foulstone, R.J. Haigh, K. Siddle, Peter R. Shepherd, Barbara T. Navé, Juleen R. Zierath |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Adult
Male medicine.medical_specialty Endocrinology Diabetes and Metabolism medicine.medical_treatment Morpholines Biology Protein Serine-Threonine Kinases Wortmannin chemistry.chemical_compound Phosphatidylinositol 3-Kinases GSK-3 Internal medicine Proto-Oncogene Proteins Internal Medicine medicine Humans Insulin Enzyme Inhibitors Phosphorylation Protein kinase A Glycogen synthase Muscle Skeletal Protein kinase B Phosphoinositide-3 Kinase Inhibitors Flavonoids Mitogen-Activated Protein Kinase 1 Phosphoinositide 3-kinase Dose-Response Relationship Drug Androstadienes Insulin receptor Endocrinology Glycogen Synthase chemistry Chromones biology.protein 3-O-Methylglucose Proto-Oncogene Proteins c-akt |
| Zdroj: | Diabetologia. 40(10) |
| ISSN: | 0012-186X |
| Popis: | Isolated skeletal muscle from healthy individuals was used to evaluate the role of phosphoinositide 3-kinase (PI 3-kinase) in insulin signalling pathways regulating mitogen activated protein kinase (MAP-kinase) and protein kinase-B and to investigate whether MAP-kinase was involved in signalling pathways regulating glucose metabolism. Insulin stimulated glycogen synthase activity (approximately 1.7 fold), increased 3-o-methylglucose transport into human skeletal muscle strips (approximately 2 fold) and stimulated phosphorylation of the p42 ERK-2 isoform of MAP-kinase. This phosphorylation of p42 ERK2 was not blocked by the PI 3-kinase inhibitors LY294002 and wortmannin although it was blocked by the MAP-kinase kinase (MEK) inhibitor PD 98059. However, PD98059 (up to 20 micromol/l) did not block insulin activation of glycogen synthase or stimulation of 3-o-methylglucose transport. Wortmannin and LY294002 did block insulin stimulation of protein kinase-B (PKB) phosphorylation and stimulation of 3-o-methylglucose transport was inhibited by wortmannin (IC50 approximately 100 nmol/l). These results indicate that MAP-kinase is activated by insulin in human skeletal muscle by a PI 3-kinase independent pathway. Furthermore this activation is not necessary for insulin stimulation of glucose transport or activation of glycogen synthase in this tissue. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink