title: A keratinocyte-specific epoxygenase, CYP2B12, metabolizes arachidonic acid with unusual selectivity, producing a single major epoxyeicosatrienoic acid.
abstract: The CYP monooxygenase, CYP2B12, is the first identified skin-specific cytochrome P450 enzyme. It is characterized by high, constitutive expression in an extrahepatic tissue, the sebaceous glands of cutaneous tissues. It is expressed exclusively in a subset of differentiated keratinocytes called sebocytes, as demonstrated by Northern blot analysis, in situ hybridization, and polymerase chain reaction. The onset of its expression coincides with the morphological appearance of sebaceous glands in the neonatal rat. Recombinant CYP2B12 produced in Escherichia coli epoxidizes arachidonic acid to 11,12- and 8,9-epoxyeicosatrienoic acids (80 and 20% of total metabolites, respectively). The identification of arachidonic acid as a substrate for this skin-specific CYP monooxygenase suggests an endogenous function in keratinocytes in the generation of bioactive lipids and intracellular signaling.
authors.affiliation: Department of Biochemistry & Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA. keeneyd@ctrvax.vanderbilt.edu
authors.forename: D S
authors.initials: DS
authors.lastname: Keeney
authors.forename: C
authors.initials: C
authors.lastname: Skinner
authors.forename: S
authors.initials: S
authors.lastname: Wei
authors.forename: T
authors.initials: T
authors.lastname: Friedberg
authors.forename: M R
authors.initials: MR
authors.lastname: Waterman
mesh_terms: D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D016718:Arachidonic Acid / Q000378:metabolism*; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis / Q000378:metabolism*; D004926:Escherichia coli; D015603:Keratinocytes / Q000201:enzymology*; D009928:Organ Specificity; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D012627:Sebaceous Glands / Q000254:growth & development; D012867:Skin / Q000201:enzymology*; D013379:Substrate Specificity; D014158:Transcription, Genetic
chemical_list: D011994:Recombinant Proteins; D016718:Arachidonic Acid; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid; C050715:8,9-epoxyeicosatrienoic acid; D003577:Cytochrome P-450 Enzyme System; C111866:CYP2B12 protein, rat; D015126:8,11,14-Eicosatrienoic Acid