title: The flavin-containing monooxygenase enzymes expressed in rabbit liver and lung are products of related but distinctly different genes.
abstract: Preparations of mRNA isolated from rabbit lung and liver were used in the construction of libraries that were screened for cDNAs encoding the pulmonary or hepatic isozyme of the flavin-containing monooxygenase. The hepatic library was screened with cDNA encoding the flavin-containing monooxygenase expressed in pig liver, and a clone containing a 2.0-kilobase insert was detected and isolated. This cDNA insert encoded a protein of 535 amino acids with a primary structure 87% identical to that of the pig flavin-containing monooxygenase. The pulmonary library was screened with polyclonal antibodies to the flavin-containing monooxygenase expressed in rabbit lung, and a clone containing a 2.6-kilobase insert was detected and isolated. Although the protein encoded by this insert also contained 535 amino acids, its primary sequence was only 56% identical to that of the liver enzyme. The sequences of several peptides obtained by digestion of the purified rabbit pulmonary flavin-containing monooxygenase with trypsin matched exactly with sequences derived from the cDNA structure. Tissue-specific distribution of mRNA for the hepatic and pulmonary isozymes of the flavin-containing monooxygenase was consistent with the distribution of protein, an indication that expression of flavin-containing monooxygenase is controlled at the level of transcription. Analysis of genomic DNA indicates that both the hepatic and pulmonary enzymes may be products of single genes.
authors.affiliation: Laboratory of Cellular and Molecular Pharmacology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709.
authors.forename: M P
authors.initials: MP
authors.lastname: Lawton
authors.forename: R
authors.initials: R
authors.lastname: Gasser
authors.forename: R E
authors.initials: RE
authors.lastname: Tynes
authors.forename: E
authors.initials: E
authors.lastname: Hodgson
authors.forename: R M
authors.initials: RM
authors.lastname: Philpot
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D015870:Gene Expression; D007527:Isoenzymes / Q000235:genetics*; D007668:Kidney / Q000032:analysis; D008099:Liver / Q000032:analysis*; D008168:Lung / Q000032:analysis*; D008969:Molecular Sequence Data; D009249:NADP / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D010105:Oxygenases / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011817:Rabbits; D012689:Sequence Homology, Nucleic Acid; D013552:Swine; D014018:Tissue Distribution
chemical_list: D007527:Isoenzymes; D012333:RNA, Messenger; D005182:Flavin-Adenine Dinucleotide; D009249:NADP; D004247:DNA; D010105:Oxygenases; C020066:dimethylaniline monooxygenase (N-oxide forming)