Cloning, expression, and characterization of three new mouse cytochrome p450 enzymes and partial characterization of their fatty acid oxidation activities.
The mammalian CYP2C subfamily is one of the largest and most complicated in the cytochrome P450 superfamily. In this report, we describe the organization of the mouse Cyp2c locus, which contains 15 genes and four pseudogenes, all of which are located in a 5.5-megabase region on chromosome 19. We cloned three novel mouse CYP2C cDNAs (designated CYP2C50, CYP2C54, and CYP2C55) from mouse heart, liver, and colon, respectively. All three cDNAs contain open reading frames that encode 490 amino acid polypeptides that are 57 to 95% identical to other CYP2Cs. The recombinant CYP2C proteins were expressed in Escherichia coli after N-terminal modification, partially purified, and shown to be active in the metabolism of both arachidonic acid (AA) and linoleic acid, albeit with different catalytic efficiencies and profiles. CYP2C50 and CYP2C54 metabolize AA to epoxyeicosatrienoic acids (EETs) primarily, and linoleic acid to epoxyoctadecenoic acids (EOAs) primarily, whereas CYP2C55 metabolizes AA to EETs and hydroxyeicosatetraenoic acids and linoleic acid to EOAs and hydroxyoctadecadienoic acids. Northern blotting and reverse transcription-polymerase chain reaction analysis reveal that CYP2C50 transcripts are abundant in liver and heart; CYP2C54 transcripts are present in liver, kidney, and stomach; and CYP2C55 transcripts are abundant in liver, colon, and kidney. Immunoblotting studies demonstrate that CYP2C50 protein is expressed in liver and heart, CYP2C54 protein is detected primarily in liver, and CYP2C55 protein is present primarily in colon. Immunohistochemistry reveals that CYP2C55 is most abundant in surface columnar epithelium in the cecum. We conclude that these new CYP2C enzymes are probably involved in AA and linoleic acid metabolism in mouse hepatic and extrahepatic tissues.
Wang
Hong
H
Laboratories of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA.
Zhao
Yun
Y
Bradbury
J Alyce
JA
Graves
Joan P
JP
Foley
Julie
J
Blaisdell
Joyce A
JA
Goldstein
Joyce A
JA
Zeldin
Darryl C
DC
D000595:Amino Acid Sequence; D000818:Animals; D002874:Chromosome Mapping; D002875:Chromosomes; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics* / Q000378:metabolism; D000072467:Cytochrome P450 Family 2; D018076:DNA, Complementary / Q000032:analysis; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
D018076:DNA, Complementary; D005227:Fatty Acids; D012333:RNA, Messenger; D011994:Recombinant Proteins; C400322:cytochrome P-450 CYP2C subfamily; D003577:Cytochrome P-450 Enzyme System; C485372:Cyp2c54 protein, mouse; C485371:Cyp2c50 protein, mouse; C485373:Cyp2c55 protein, mouse; D000072467:Cytochrome P450 Family 2