MARMOSET CYP1A2 - PRIMARY STRUCTURE AND CONSTITUTIVE EXPRESSION IN LIVERS

Complementary DNA of marmoset CYP1A2 was isolated by means of screenin g the cDNA library and reverse-transcriptase polymerase chain reaction , The deduced amino acid sequence of marmoset CYP1A2 consisted of 516 residues and showed 88.2 and 90.0% identities to corresponding forms i n human and cynomolgus monkey, respectively, S1 nuclease protection as say demonstrated that CYP1A2 mRNA was expressed constitutively in the liver, but not in the lung, kidney and small intestine, The level of C YP1A2 mRNA in the liver was increased by treatment with 3-methylcholan threne and polychlorinated biphenyls, Marmoset CYP1A2 expressed in rec ombinant yeast activated 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) and 2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline (MeIQx) efficientl y, and also activated 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), but at a relatively lower rate in the umu mutagenicity test, Marmoset CYP1A2 also showed ethoxyresorufin O-de-ethylase activity, Ba sed on these results, we demonstrate that marmosets constitutively exp ress CYP1A2 in the liver as in humans.