Biochemical and Biophysical Research Communications, Vol.345, No.2, 568-572, 2006
Isolation and properties of the CYP2D25 promoter: Transcriptional regulation by vitamin D-3 metabolites
Previous studies have suggested that hepatic production of 25-hydroxyvitamin D-3 may be suppressed by 1 alpha,25-dihydroxyvitamin D-3. However, the molecular details of these observations have not been clarified. In the current study, the 5'-flanking DNA sequence of CYP2D25, a porcine microsomal vitamin D 25-hydroxylase, was isolated and analyzed. The CYP2D25 promoter contains a putative vitamin D response element (VDRE). The promoter activity was markedly suppressed by la,25-dihydroxyvitamin D-3 and 25-hydroxyvitamin D-3 in presence of vitamin D receptor (VDR). The data suggest that VDR-mediated inhibition of 25-hydroxylase(s) by vitamin D-3 metabolites at the transcriptional level may play an important role in the regulation of 25-hydroxyvitamin D-3 production in liver and other tissues. (c) 2006 Elsevier Inc. All rights reserved.