Signal transduction by the erythropoietin receptor: evidence for the activation of phospholipases A2 and C
| Autor: | Jen-Sie Tou, Barbara S. Beckman, S. Clejan, M. Mason-Garcia |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Physiology
Receptors Cell Surface Leukotriene B4 Phospholipases A Diglycerides chemistry.chemical_compound Phospholipase A2 Fetus Hydroxyeicosatetraenoic Acids Receptors Erythropoietin Animals 12-Hydroxy-5 8 10 14-eicosatetraenoic Acid Erythropoietin Cells Cultured Phospholipids Diacylglycerol kinase Arachidonic Acid biology Phospholipase C Inositol trisphosphate Cell Biology Phosphatidic acid Rhc80267 Enzyme Activation Lipoprotein Lipase chemistry Biochemistry Liver Type C Phospholipases biology.protein lipids (amino acids peptides and proteins) Arachidonic acid Signal transduction Signal Transduction |
| Zdroj: | The American journal of physiology. 262(5 Pt 1) |
| ISSN: | 0002-9513 |
| Popis: | Erythropoietin (Ep) is the peptide growth factor whose actions on the erythroid progenitor cell induce terminal differentiation. However, the intracellular signaling system that is activated by Ep is poorly understood. Our previous studies have implicated the lipoxygenase metabolites of arachidonic acid in the actions of Ep. In this study, we report an early (30 s to 5 min) increase in levels of two lipoxygenase metabolites: leukotriene B4 (LTB4; 3- to 5-fold) and 12-hydroxyeicosatetraenoic acid (12-HETE; 2-fold). These responses were blocked by an antibody to Ep, by lipoxygenase inhibitors, or by 1,6-di[O-(carbamoyl)cyclohexanone oxime]hexane (RHC80267), an inhibitor of diacylglycerol (DAG) lipase. RHC 80267 also significantly inhibited Ep-mediated proliferation. Ep induced the release of [3H]arachidonic acid from cellular phospholipids at 5 min and also increased DAG accumulation at 1 min with a maximum increase of 68.2% over control seen at 30 min. No increase in levels of inositol trisphosphate or phosphatidic acid was observed in response to Ep. Taken together, these data suggest that the signal transduction pathway of the Ep receptor includes the activation of phospholipases A2 and C, resulting in the liberation of DAG and arachidonate and the subsequent formation of LTB4 and 12-HETE. |
| Databáze: | OpenAIRE |
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