G Protein-coupled Receptor-induced Sensitization of Phospholipase C Stimulation by Receptor Tyrosine Kinases
| Autor: | Markus Frings, Paschal A. Oude Weernink, Marie-Luise Mono, Martina Schmidt, Yuanjian Guo, Karl Jakobs, Sandrine Evellin, Li Han |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Agonist
medicine.medical_specialty Protein Kinase C-alpha medicine.drug_class Inositol Phosphates Stimulation Inositol 1 4 5-Trisphosphate Transfection Biochemistry Receptor tyrosine kinase Cell Line chemistry.chemical_compound Adenosine Triphosphate GTP-Binding Proteins Internal medicine Protein Kinase C beta Lysophosphatidic acid Muscarinic acetylcholine receptor medicine Humans Molecular Biology Protein Kinase C Protein kinase C G protein-coupled receptor Platelet-Derived Growth Factor Receptor Muscarinic M3 Receptor Muscarinic M2 Epidermal Growth Factor Phospholipase C biology Receptor Protein-Tyrosine Kinases Cell Biology Receptors Muscarinic Recombinant Proteins Cell biology Isoenzymes Kinetics Endocrinology chemistry Type C Phospholipases biology.protein Carbachol |
| Zdroj: | Journal of Biological Chemistry. 275:32603-32610 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m004784200 |
| Popis: | Activation of stably expressed M(2) and M(3) muscarinic acetylcholine receptors (mAChRs) as well as of endogenously expressed lysophosphatidic acid and purinergic receptors in HEK-293 cells can induce a long lasting potentiation of phospholipase C (PLC) stimulation by these and other G protein-coupled receptors (GPCRs). Here, we report that GPCRs can induce an up-regulation of PLC stimulation by receptor tyrosine kinases (RTKs) as well and provide essential mechanistic characteristics of this sensitization process. Pretreatment of HEK-293 cells for 2 min with carbachol, a mAChR agonist, lysophosphatidic acid, or ATP, followed by agonist washout, strongly increased (by 2-3-fold) maximal PLC stimulation (measured >/=40 min later) by epidermal growth factor and platelet-derived growth factor, but not insulin, and largely enhanced PLC sensitivity to these RTK agonists. The up-regulation of RTK-induced PLC stimulation was cycloheximide-insensitive and was observed for up to approximately 90 min after removal of the GPCR agonist. Sensitization of receptor-induced PLC stimulation caused by prior M(2) mAChR activation was fully prevented by pertussis toxin and strongly reduced by expression of Gbetagamma scavengers. Furthermore, inhibition of conventional protein kinase C (PKC) isoenzymes and chelation of intracellular Ca(2+) suppressed the sensitization process, while overexpression of PKC-alpha, but not PKC-betaI, further enhanced the M(2) mAChR-induced sensitization of PLC stimulation. None of these treatments affected acute PLC stimulation by either GPCR or RTK agonists. Taken together, short term activation of GPCRs can induce a strong and long lasting sensitization of PLC stimulation by RTKs, a process apparently involving G(i)-derived Gbetagammas as well as increases in intracellular Ca(2+) and activation of a PKC isoenzyme, most likely PKC-alpha. |
| Databáze: | OpenAIRE |
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