title: Synergistic stimulation of S-adenosylmethionine decarboxylase activity by Ca2+ ionophore A23187, cholera toxin and 1-oleoyl-2-acetylglycerol.
abstract: The Ca2+ ionophore A23187 induced S-adenosylmethionine decarboxylase in guinea-pig lymphocytes, and cholera toxin stimulated the induction synergistically. The activator of protein kinase C, 1-oleoyl-2-acetylglycerol, did not induce S-adenosylmethionine decarboxylase activity but potentiated the enzyme activity induced by A23187 or by A23187 and cholera toxin. The addition of both A23187 and cholera toxin induced S-adenosylmethionine decarboxylase, but the further addition of 1-oleoyl-2-acetylglycerol or 12-O-tetradecanoylphorbol 13-acetate did not potentiate the enzyme induction in protein kinase-C-down-regulated cells that had been treated with 12-O-tetradecanoylphorbol 13-acetate for 18 h. These results suggest that a Ca2+-dependent pathway, other than that for protein kinase C, is essential for the induction of S-adenosylmethionine decarboxylase and that a cAMP-dependent pathway and also protein kinase C are involved in the potentiation of the induction.
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000097:blood*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002262:Carboxy-Lyases / Q000097:blood*; D002772:Cholera Toxin / Q000494:pharmacology*; D004075:Diglycerides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004790:Enzyme Induction / Q000187:drug effects; D005989:Glycerides / Q000494:pharmacology*; D006168:Guinea Pigs; D008214:Lymphocytes / Q000201:enzymology; D011493:Protein Kinase C / Q000378:metabolism
chemical_list: D004075:Diglycerides; D005989:Glycerides; D000001:Calcimycin; C038237:1-oleoyl-2-acetylglycerol; D002772:Cholera Toxin; D011493:Protein Kinase C; D002262:Carboxy-Lyases; D012437:Adenosylmethionine Decarboxylase