title: Microsome-mediated stimulation of the aminoacylation of rat liver initiator transfer ribonucleic acid by benzo[alpha]pyrene and 3,3-dimethyl-1-phenyltriazene.
abstract: The charging of initiator tRNAmetF with L-methionine was significantly stimulated by pre-incubation of unfractionated tRNA from rat liver with benzo [alpha]pyrne (BP) or 3,3-dimethyl-1-phenyltriazine (DMPT). The presence of microsomal enzymes from rat liver and of NADPH was absolutely required for this effect. Maximum enhancement was obtained after 60 min of incubation with 10(-4)-10(-8) mumol/ml of either compound tested. It appears that either proximate carcinogen, BP or DMPT, must be converted by microsomal enzymes into its direct-acting metabolites (ultimate carcinogens) which interact with initiator tRNA and thereby specifically modulate its aminoacylation.
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D000818:Animals; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000494:pharmacology*; D001711:Biotransformation; D002273:Carcinogens; D008715:Methionine / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D012343:RNA, Transfer / Q000302:isolation & purification; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012358:RNA, Transfer, Met; D051381:Rats; D013268:Stimulation, Chemical; D013997:Time Factors; D014226:Triazenes / Q000494:pharmacology*
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D012346:RNA, Transfer, Amino Acyl; D012358:RNA, Transfer, Met; D014226:Triazenes; C024988:tRNA, formylmethionine-; D001564:Benzo(a)pyrene; D009249:NADP; C008848:1-phenyl-3,3-dimethyltriazene; D012343:RNA, Transfer; D008715:Methionine; D000604:Amino Acyl-tRNA Synthetases