title: Multiple constitutive but phenobarbital-inducible rat hepatic nuclear RNA species homologous to a novel cytochrome P-450 cDNA.
abstract: A cDNA clone, pPB8, representing partial information for a phenobarbital-inducible rat hepatic cytochrome P-450, immunochemically related to cytochrome P-450b and/or P-450e, hybridized to multiple hepatic nuclear RNA species. In addition to the 3.7 +/- 0.2 kb mRNA encoding this novel cytochrome P-450 isozyme, pPB8 hybridized to nuclear RNAs of 4.9 +/- 0.3, 5.4, 5.7 +/- 0.2, and 6.3 +/- 0.1 kb. These nuclear RNAs were constitutively expressed and were inducible to various extents by phenobarbital administration. The time course of induction of these nuclear RNA components suggested product-precursor relationships. A "full-length" cDNA clone, pPB8/7, synthesized from poly(A)+ RNA homologous to pPB8, detected two mRNA species of 4.6 and 1.8 kb. The 4.6 kb nuclear RNA was inducible by 3-methylcholanthrene, Aroclor 1254, and phenobarbital, while the 1.8 kb nuclear RNA was not appreciably affected. It is suggested that pPB8 and pPB8/7 were synthesized from distinct mRNAs that share homology in their 3' regions.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000235:genetics*; D004247:DNA / Q000032:analysis*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010634:Phenobarbital / Q000494:pharmacology*; D010957:Plasmids; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D010634:Phenobarbital