Ds. Keeney et al., A KERATINOCYTE-SPECIFIC EPOXYGENASE, CYP2B12, METABOLIZES ARACHIDONIC-ACID WITH UNUSUAL SELECTIVITY, PRODUCING A SINGLE MAJOR EPOXYEICOSATRIENOIC ACID, The Journal of biological chemistry, 273(15), 1998, pp. 9279-9284
The CYP monooxygenase, CYP2B12, is the first identified skin-specific
cytochrome P450 enzyme. It is characterized by high, constitutive expr
ession in an extrahepatic tissue, the sebaceous glands of cutaneous ti
ssues. It is expressed exclusively in a subset of differentiated kerat
inocytes 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 g
lands in the neonatal rat. Recombinant CYP2B12 produced in Escherichia
coli epoxidizes arachidonic acid to 11,12- and 8,9-epoxyeicosatrienoi
c acids (80 and 20% of total metabolites, respectively). The identific
ation of arachidonic acid as a substrate for this skin-specific CYP mo
nooxygenase suggests an endogenous function in keratinocytes in the ge
neration of bioactive lipids and intracellular signaling.