Cytochrome P450 family 27 subfamily B member 1 (CYP27B1) and CYP24A1 function to maintain physiological levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in the kidney. Renal Cyp27b1 and Cyp24a1 expression levels are transcriptionally regulated in a highly reciprocal manner by parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and 1,25(OH)2D3. In contrast, Cyp24a1 regulation in nonrenal target cells (NRTCs) is limited to induction by 1,25(OH)2D3. Herein, we used ChIP-Seq analyses of mouse tissues to identify regulatory regions within the Cyp24a1 gene locus.
