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.

作者：James P. Hardwick, Byeong Jun Song, Eliezer Huberman, Frank J. Gonzalez · 发表于：Journal of Biological Chemistry · 年份：1987 · DOI：10.1016/s0021-9258(19)75857-8 · 被引用次数：317 · 研究领域：Metabolism and Genetic Disorders、Lipid metabolism and biosynthesis、Alcohol Consumption and Health Effects

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 termin...