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630595 
Journal Article 
Isolation, complementary DNA sequence, and regulation of rat hepatic lauric acid omega-hydroxylase (cytochrome P-450LA omega): Identification of a new cytochrome P-450 gene family 
Hardwick, JP; Song, BJ; Huberman, E; Gonzalez, FJ 
1987 
Yes 
Journal of Biological Chemistry
ISSN: 0021-9258
EISSN: 1083-351X 
262 
2 
801-810 
English 
3027069 
Lauric acid omega-hydroxylase (cytochrome P-450LA omega) was purified from livers of rats that had been given the hypolipidemic drug clofibrate. Immunoblot analysis with anti-cytochrome P-450LA omega antibody revealed the presence of two clofibrate-induced cytochrome P-450 proteins in both liver and kidney. This antibody was used to screen a lambda gt11 expression library constructed from liver mRNA isolated from rats given clofibrate. The clone, pP-450LA omega, was isolated and found to contain 2062 base pairs with an open reading frame of 509 amino acids (Mr 58,222). The pP-450LA omega cDNA insert was placed in the yeast expression vector pAAH5, and the resultant plasmid expressed a protein of the same size and activity as cytochrome P-450LA omega. The mechanism of the regulation of the cytochrome P-450LA omega gene by hypolipidemic agents was examined. The rate of cytochrome P-450LA omega gene transcription was increased as early as 1 h after administration of clofibrate, and this increase was followed by an elevation of cytochrome P-450LA omega mRNA, immunochemically detectable protein, and cytochrome P-450LA omega activity. In contrast, no increase in transcriptional activity was detected after clofibrate administration for the cytochrome P-450PCN or P-450b/e genes. The cytochrome P-450LA omega has several structural features in common with other cytochrome P-450s, including a conserved cysteine-containing heme-binding fifth ligand fragment and a hydrophobic amino terminus. Overall, cytochrome P-450LA omega shared less than 35% cDNA nucleotide and amino acid similarity with cytochromes P-450c, P-450d, P-450e, and P-450PCN, indicating that it is a member of a new cytochrome P-450 gene family. Southern blot analysis indicates that this family contains two or three genes