n/a
NM_000896
NM_001199208
NM_001199209
NP_000887
NP_001186137
NP_001186138
n/a
Leukotriene-B(4) omega-hydroxylase 2 is an enzyme that in humans is encoded by the CYP4F3 gene. CYP4F3 encodes two distinct enzymes, CYP4F3A and CYP4F3B, which originate from the alternative splicing of a single pre-mRNA precursor molecule; selection of either isoform is tissue-specific with CYP3F3A being expressed mostly in leukocytes and CYP4F3B mostly in the liver.
The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids, fatty acids and other lipids. CYP4F3 actually encodes two splice-variants, CYP4F3A and CYP4F3B, of the cytochrome P450 superfamily of enzymes. The gene is part of a cluster of cytochrome P450 genes on chromosome 19. Another member of this family, CYP4F8, is approximately 18 kb away. Both variants localize on the endoplasmic reticulum and metabolize leukotriene B4 and very likely 5-hydroxyeicosatetraenoic acid, 5-oxo-eicosatetraenoic acid, and 12-hydroxyeicosatetraenoic acid by an omega oxidation reaction, i.e. by adding a hydroxyl residue to their terminal (i.e. C-20) carbon. This addition starts the process of inactivating and degrading all of these well-known mediators of inflammation and/or allery. CYP3FA is the major enzyme accomplishing these omega oxidations in leukocytes. The hydroxylation-induced inactivation of these mediators, perhaps particularly of leukotriene B4, may underlie the proposed roles of these cytochromes in dampening inflammatory responses as well as the reported associations of certain CYP4F3 single nucleotide variants (SNPs) with human Krohn's disease (SNPs are designated Rs1290617 and rs1290620 and Celiac disease (rs1290622 and rs1290625).