Diacylglycerols, unlike phorbol esters, do not induce homologous desensitization or down-regulation of protein kinase C in Swiss 3T3 cells.
Addition of 1-oleoyl-2-acetyl-glycerol (OAG), 1,2-dioctanoyl-glycerol (diC8) or phorbol-12, 13-dibutyrate (PDBu) to cultures of Swiss 3T3 cells rapidly increases the phosphorylation of the Mr 80,000 protein kinase C (PKC) substrate, inhibits EGF binding and stimulates DNA synthesis. Prolonged incubation (40 h) with PDBu completely blocked these responses to all agents and down-regulated PKC. In contrast, a similar treatment with OAG or diC8, at mitogenic concentrations, neither induced homologous cellular desensitization nor decreased the immunoreactive level or activity of PKC. The results show that PKC down-regulation can be dissociated from PKC-mediated mitogenesis in Swiss 3T3 cells.
Issandou
M
M
Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK.
Rozengurt
E
E
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004075:Diglycerides / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005989:Glycerides / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D010703:Phorbol Esters / Q000494:pharmacology*; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*
D004075:Diglycerides; D005989:Glycerides; D007328:Insulin; D010703:Phorbol Esters; D010750:Phosphoproteins; D011493:Protein Kinase C