A Nuclear Protein Essential for Binding of Rat 1,25-Dihydroxyvitamin D_3 Receptor to Its Response Elements
Abstract
Recombinant 1,25-dihydroxyvitamin D3 receptor from a baculovirus expression system requires a mammalian-derived nuclear accessory protein for binding to a vitamin D response element (DRE). This was established by electrophoretic mobility shift analyses using radiolabeled DNA probes consisting of DREs from two vitamin D-responsive genes. Mammalian nuclear extract was also required for the binding of wild-type porcine vitamin D receptor to a DRE. Surprisingly, the accessory factor-dependent formation of receptor-DRE complex was independent of exogenous 1,25-dihydroxyvitamin D3. A 59- to 64-kDa accessory protein from porcine intestinal nuclear extract was identified by size-exclusion chromatography. Nuclear extracts from rat liver and kidney contained accessory factor, whereas smaller amounts were detected in heart muscle. Spleen and skeletal muscle contained no detectable accessory factor.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- January 1992
- DOI:
- 10.1073/pnas.89.1.256
- Bibcode:
- 1992PNAS...89..256R