Identification of a vitamin D-responsive element in the 5'-flanking region of the rat 25-hydroxyvitamin D3 24-hydroxylase gene

• Published in: The Journal of biological chemistry Vol. 269; no. 14; pp. 10545 - 10550
• Main Authors: OHYAMA, Y, OZONO, K, UCHIDA, M, SHINKI, T, KATO, S, SUDA, T, YAMAMOTO, O, NOSHIRO, M, KATO, Y
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 08.04.1994
• Subjects: Animals; Base Sequence; Biological and medical sciences; Cells, Cultured; Cytochrome P-450 Enzyme System - genetics; DNA; Fundamental and applied biological sciences. Psychology; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Oligodeoxyribonucleotides; Promoter Regions, Genetic; Rats; Regulatory Sequences, Nucleic Acid; Sequence Deletion; Steroid Hydroxylases - genetics; Transcription. Transcription factor. Splicing. Rna processing; Vitamin D - analogs & derivatives; Vitamin D - pharmacology; Vitamin D3 24-Hydroxylase; Vertebrata; Mammalia; Transcription; Rat; Vitamin D; Enzyme; Transcription promoter; Repeated sequence; Hydroxylase; Rodentia; Vitamin; Gel retardation technique
• DOI: 10.1016/s0021-9258(17)34094-2
• ISSN: 0021-9258

The 5'-flanking region of the rat vitamin D3 24-hydroxylase (P450cc24) gene was examined and a vitamin D-responsive element (VDRE) responsible for the 1 alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) enhancement was identified. Unidirectional deletion analyses of the 5'-flanking region indicated that the region [-167/-102] is involved in vitamin D responsiveness. Further functional analyses showed that the segment [-204/-129] conferred the hormone responsiveness in an orientation-independent manner when it was placed upstream to the heterologous thymidine kinase promoter or the rabbit beta-globin promoter. The segment [-204/-129] contained two direct repeat motifs homologous to other VDREs found in the osteocalcin and osteopontin genes. Synthetic oligonucleotides containing the putative VDRE were used for functional analyses and gel mobility shift assays. The proximal [-151/-137], but not the distal [-169/-155] direct repeat activated the transcription in response to 1,25-(OH)2D3 through the beta-globin promoter. Furthermore, the proximal direct repeat formed a complex with the vitamin D receptor and a nuclear accessory factor(s) from COS cells (or retinoid X receptor) in the presence of 1,25-(OH)2D3. These results indicate that a direct repeat motif, AGGTGAgt-gAGGGCG, located at -151 base pairs upstream in the antisense strand binds to a heterologous dimer consisting of the VDR occupied with 1,25-(OH)2D3 and the nuclear accessory factor and that it plays a critical role in mediating the vitamin D enhancement of the rat P450cc24 gene expression.