Mastoparan causes cell permeabilisation and delayed activation of DNA synthesis in Swiss 3T3 fibroblasts.
Mastoparan, a tetradecapeptide from wasp venom, preferentially activates the heterotrimeric G proteins, Go and Gi by promoting GDP/GTP exchange. The peptide was originally identified as a potent secretagogue and has since been shown to promote DNA synthesis in Swiss 3T3 fibroblasts. Here, we have shown that mastoparan (10-20 microM), either alone or in combination with the co-mitogen insulin, had no effect on DNA synthesis when incubated with cells for 24 h. However, in the presence of insulin, the peptide evoked a small increase in DNA synthesis after incubation for 40 h. Thus, unlike other mitogens, mastoparan caused a delayed activation of DNA synthesis. At concentrations of mastoparan (15-17.5 microM) which promoted DNA synthesis, the peptide caused a rapid release of lactate dehydrogenase from the cells. These data suggest that the mitogenic action of mastoparan occurs by a mechanism distinct from that of physiological mitogens.
Pullan
S
S
Department of Human Anatomy and Cell Biology, University of Liverpool, UK.
Pennington
S R
SR
D016475:3T3 Cells; D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects*; D019204:GTP-Binding Proteins / Q000187:drug effects; D007328:Insulin / Q000494:pharmacology; D036341:Intercellular Signaling Peptides and Proteins; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D010455:Peptides; D014176:Protein Biosynthesis; D014862:Wasp Venoms / Q000494:pharmacology*
D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D014862:Wasp Venoms; C037500:mastoparan; D004247:DNA; D007770:L-Lactate Dehydrogenase; D019204:GTP-Binding Proteins