Insulin receptor substrate 1 is phosphorylated by the serine kinase activity of phosphatidylinositol 3-kinase
| Autor: | Jean-François Tanti, T Grémeaux, Y. Le Marchand-Brustel, E Van Obberghen |
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| Rok vydání: | 1994 |
| Předmět: |
Protein Serine-Threonine Kinases
Biochemistry Substrate Specificity Mice Phosphatidylinositol 3-Kinases Insulin receptor substrate Animals Protein phosphorylation Phosphorylation Kinase activity Molecular Biology MAPK14 Serine/threonine-specific protein kinase biology Chemistry 3T3 Cells Cell Biology Receptor Insulin IRS2 Enzyme Activation Phosphotransferases (Alcohol Group Acceptor) Insulin receptor biology.protein Research Article |
| Zdroj: | Biochemical Journal. 304:17-21 |
| ISSN: | 1470-8728 0264-6021 |
| Popis: | Insulin receptor substrate (IRS) 1, which is tyrosine phosphorylated in response to insulin, presents multiple serine/threonine phosphorylation sites. To search for a serine kinase activity towards IRS 1, immunoprecipitates from basal or stimulated 3T3-L1 adipocytes were used in an in vitro kinase assay. When IRS 1 was isolated from insulin-treated cells, serine phosphorylation of IRS 1 occurred, which we attribute to the kinase activity of the phosphatidylinositol 3-kinase (PI3-kinase). Importantly, in an in vitro reconstitution assay, an excess of the PI3-kinase subunit prevents this phosphorylation. Together, our results suggest that following insulin stimulation, PI3-kinase associates with IRS 1, allowing for its serine phosphorylation. This phosphorylation event could play a role in the modulation of insulin signalling. |
| Databáze: | OpenAIRE |
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