Stimulation of tubulin tyrosinolation in rabbit leukocytes evoked by the chemoattractant formyl-methionyl-leucyl-phenylalanine.
Cellular tubulin is subject to a posttranslational modification involving the reversible addition to tyrosine through peptide linkage to the C-terminal glutamate of the alpha-chain. The synthetic peptide chemoattractant, N-formyl-methionyl-leucyl-phenylalanine, causes a specific, dose-dependent stimulation of tubulin tyrosinolation in rabbit leukocytes. This stimulation is prevented by carbobenzoxy-phenylalanyl-methionine, benzoyl-tyrosine ethylester, and nordihydroguaiaretic acid, which are all inhibitors of chemotaxis presumed to act via membrane-associated events. The combination of 3-deazaadenosine and homocysteine thiolactone, which inhibits phospholipid methylation, and quinacrine, an inhibitor of phospholipase A2, also abolishes the response to the peptide. Colchicine, however, which causes a marked disassembly of cellular microtubules in these cells and also inhibits chemotaxis, does not have any inhibitory effect on the basal or peptide-stimulated rate of tubulin tyrosinolation. In contrast, taxol, a microtubule-stabilizing agent, has an inhibitory effect on both the basal and peptide-stimulated tyrosine incorporation. Taxol also inhibits chemotaxis in rabbit leukocytes. The results strongly suggest the role of closely linked membrane-cytoskeleton interactions in leukocyte chemotaxis, in which tyrosinolation of tubulin may be functionally involved.
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002634:Chemotaxis, Leukocyte; D003078:Colchicine / Q000378:metabolism / Q000494:pharmacology; D007962:Leukocytes / Q000378:metabolism*; D008715:Methionine / Q000031:analogs & derivatives*; D009239:N-Formylmethionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009842:Oligopeptides / Q000494:pharmacology*; D017239:Paclitaxel; D010453:Peptide Synthases / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits; D014404:Tubulin / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
D000470:Alkaloids; D009842:Oligopeptides; D014404:Tubulin; D009239:N-Formylmethionine; D014443:Tyrosine; D009240:N-Formylmethionine Leucyl-Phenylalanine; D008715:Methionine; D010453:Peptide Synthases; C023213:tyrosyltubulin ligase; D017239:Paclitaxel; D003078:Colchicine