SCIENCE@home

Expression of the CYP4F3 Gene

P. Christmas,Sonia R. Ursino,J. Fox,R. Soberman

Published 1999 in Journal of Biological Chemistry

ABSTRACT

Cytochrome P450 4F3 (CYP4F3) catalyzes the inactivation of leukotriene B4 by ω-oxidation in human neutrophils. To understand the regulation of CYP4F3 expression, we analyzed the CYP4F3 gene and cloned a novel isoform (CYP4F3B) that is expressed in fetal and adult liver, but not in neutrophils. The CYP4F3 gene contains 14 exons and 13 introns. The cDNAs for CYP4F3A (the neutrophil isoform) and CYP4F3B have identical coding regions, except that they contain exons 4 and 3, respectively. Both exons code for amino acids 66–114 but share only 27% identity. When expressed in COS-7 cells, the K m of CYP4F3B was determined to be 26-fold higher than the K m of CYP4F3A using leukotriene B4 as a substrate. 5′-Rapid amplification of cDNA end studies reveal that the CYP4F3A and CYP4F3B transcripts have 5′-termini derived from different parts of the gene and are initiated from distinct transcription start sites located 519 and 71 base pairs (bp), respectively, from the ATG initiation codon. A consensus TATA box is located 27 bp upstream of the CYP4F3B transcription start site, and a TATA box-like sequence is located 23 bp upstream of the CYP4F3A transcription start site. The data indicate that the tissue-specific expression of functionally distinct CYP4F3 isoforms is regulated by alternative promoter usage and mutually exclusive exon splicing.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-40 of 40 references · Page 1 of 1

CITED BY

Showing 1-84 of 84 citing papers · Page 1 of 1