Identification of a vitamin D-responsive element in the 5'-flanking region of the rat 25-hydroxyvitamin D3 24-hydroxylase gene
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 indica...
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Published in | The Journal of biological chemistry Vol. 269; no. 14; pp. 10545 - 10550 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Bethesda, MD
American Society for Biochemistry and Molecular Biology
08.04.1994
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Subjects | |
Online Access | Get full text |
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Summary: | 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. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/s0021-9258(17)34094-2 |