Direct demonstration of the activation of UDP-N-acetylgalactosamine: [GM3]N-acetylgalactosaminyltransferase by cyclic AMP.
Treatment of NG108-15 cells in culture with the opiate peptide [D-Ala2,D-Leu5]enkephalin produces maximal inhibition of cyclic AMP synthesis in less than 15 min. The activity of [GM3]:N-acetylgalactosaminyltransferase is similarly inhibited, but maximal inhibition is not observed for at least 30 min following the addition of [D-Ala2,D-Leu5]enkephalin. Conversely, the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine rapidly potentiates the intracellular accumulation of cyclic AMP and, in a more gradual fashion, increases [GM3]:N-acetylgalactosaminyltransferase activity. The reductions in the activity of [GM3]:N-acetylgalactosaminyltransferase that occur following treatment of NG108-15 cells with indomethacin argues for a direct role of cyclic AMP in the observed changed in [GM3]:N-acetylgalactosaminyltransferase activity. By adding low concentrations of cyclic AMP (but not cyclic GMP) to microsomes derived from neonatal rat brain, we were able to demonstrate a dose-dependent phosphorylation of membrane protein and subsequent doubling of [GM3]:N-acetylgalactosaminyltransferase activity.
Scheideler
M A
MA
Dawson
G
G
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000201:enzymology; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D004789:Enzyme Activation / Q000187:drug effects; D005700:Galactosyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005910:Glioma / Q000201:enzymology; D007700:Kinetics; D051379:Mice; D008861:Microsomes / Q000201:enzymology; D017350:N-Acetylgalactosaminyltransferases; D009447:Neuroblastoma / Q000201:enzymology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D015056:1-Methyl-3-isobutylxanthine; D000242:Cyclic AMP; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D005700:Galactosyltransferases; D017350:N-Acetylgalactosaminyltransferases; D010750:Phosphoproteins; D011494:Protein Kinases; D000097763:Polypeptide N-acetylgalactosaminyltransferase; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase