Open AccesscDNA Cloning and Analysis of Chick‐Embryo‐Liver Cytochrome P‐450 mRNA Induced by Porphyrinogenic Drugs
Author(s) -
BROOKER John D.,
O'CONNOR Reina
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb07055.x
Subject(s) - messenger rna , complementary dna , cytochrome , microbiology and biotechnology , embryo , cytochrome p450 , biology , cdna library , hemeprotein , rna , gene expression , chemistry , biochemistry , heme , gene , enzyme
Hepatic microsomal cytochrome P‐450 was elevated in 17‐day chick embryos by combined administration of the porphyrinogenic drugs 2‐allyl‐2‐isopropylacetamide and 3,5‐diethoxycarbonyl‐1,4‐dihydrocollidine. Increased apoprotein levels were the result of de novo protein synthesis; in vitro obtained translation data suggested that cytochrome P‐450 mRNA levels were elevated. A 1000‐base cDNA sequence for the drug‐induced cytochrome P‐450 mRNA was isolated from a chick embryo cDNA ‘library’ and this was used as a specific probe to investigate drug‐mediated induction of cytochrome P‐450 mRNA. RNA‐DNA ‘dot’ hybridisation studies demonstrated that drug treatment led to a 3–5‐fold increase in the level of this mRNA and that the mRNA was predominantly associated with membrane‐bound polyribosomes. Treatment of embryos with the drugs individually demonstrated that both of them induced synthesis of the same mRNA. These studies show directly that treatment of chick embryos with 2‐allyl‐2‐isopropylacetamide or 3,5‐diethoxycarbonyl‐1,4‐dihydrocollidine caused increased levels of cytochrome P‐450 mRNA and suggest that this involved increased transcription of the gene.