Lysophosphatidylcholine activates mesangial cell PKC and MAP kinase by PLCgamma-1 and tyrosine kinase-Ras pathways
| Autor: | Vaijinath S. Kamanna, Daeyoung D. Roh, Nosratola D. Vaziri, Michael A. Kirschenbaum, Babu V. Bassa |
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| Rok vydání: | 1999 |
| Předmět: |
Physiology
MAPK7 Biology Mitogen-activated protein kinase kinase MAP2K7 Mice Animals ASK1 Phosphorylation Protein kinase C Cells Cultured Protein Kinase C MAP kinase kinase kinase Phospholipase C gamma Lysophosphatidylcholines Protein-Tyrosine Kinases Cell biology Glomerular Mesangium Enzyme Activation Isoenzymes Biochemistry Type C Phospholipases Calcium-Calmodulin-Dependent Protein Kinases ras Proteins lipids (amino acids peptides and proteins) Cyclin-dependent kinase 9 Tyrosine kinase Signal Transduction |
| Zdroj: | The American journal of physiology. 277(3) |
| ISSN: | 0002-9513 |
| Popis: | Although lysophosphatidylcholine (LPC)-mediated cellular responses are attributed to the activation of protein kinase C (PKC), relatively little is known about the upstream signaling mechanisms that regulate the activation of PKC and downstream mitogen-activated protein (MAP) kinase. LPC activated p42 MAP kinase and PKC in mesangial cells. LPC-mediated MAP kinase activation was inhibited (but not completely) by PKC inhibition, suggesting additional signaling events. LPC stimulated protein tyrosine kinase (PTK) activity and induced Ras-GTP binding. LPC-induced MAP kinase activity was blocked by the PTK inhibitor genistein. Because LPC increased PTK activity, we examined the involvement of phospholipase Cγ-1 (PLCγ-1) as a key participant in LPC-induced PKC activation. LPC stimulated the phosphorylation of PLCγ-1. PTK inhibitors suppressed LPC-induced PKC activity, whereas the same had no effect on phorbol 12-myristate 13-acetate-mediated PKC activity. Other lysophospholipids [e.g., lysophosphatidylinositol and lysophosphatidic acid (LPA)] also induced MAP kinase activity, and only LPA-induced MAP kinase activation was sensitive to pertussis toxin. These results indicate that LPC-mediated PKC activation may be regulated by PTK-dependent activation of PLCγ-1, and both PKC and PTK-Ras pathways are involved in LPC-mediated downstream MAP kinase activation. |
| Databáze: | OpenAIRE |
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