Molecular cloning, characterization of a homologue of cytochrome P450s 4F7 in Pseudosciaena crocea

CYP4F7 is amember of the 4F subfamily of the Cytochrome P450,which plays a vital role in the course of either catalyzing and regulating the metabolism of endogenous substances or activating and degrading exogenetic substances by transferring electrons.A CYP4F7 cDNA sequence (GenBank accession number:EU 169141) was isolated and identified from the total RNA of Pseudosciaena crocea kidney using the combined methods of BD SMART^TM cDNA synthesis and RACE-PCR.The sequence of CYP4F7 cDNA is 1934 bp which contains a 5'UTR of 59bp and a 3'UTR of 264bp,and an open reading frame with 1611bp that encodes a protein of 536 amino acids.The amino acid sequence of P.crocea CYP4F7 shared 67%~71% of residue identity with the CYP4F subfamily of other high mammals such as human and mice,and shared the highest identity of 91% with sea bass,Dicentrarchuslabrax.Semi-quantitative RT-PCR analysis showed that mRNA expression of CYP4F7 can be detected in the spleen,heart,liver,anterior kidney,kidney and gills,but not in the intestine and muscle in the normal group and the lipopo lysaccharide (LPS)-stimulated group of P.crocea,in which the higher expression was found in the spleen and liver.The expression of the CYP4F7 in all these tissues examined showed some decrease in the LPS-treated P.crocea compared with normal P.crocea,suggesting that LPS might be an inhibit or of cytochrome P450 CYP4F7 gene and CYP4F7 might be related to large yellow croaker P.crocea immune response.