The apparent hormonal form of cholecalciferol, 1,25-dihydroxycholecalciferol (1,25-(OH)2-CC), was incubated with intestinal mucosa homogenates and whole intestinal tissue, in vitro. After 40-70 min, 1,25-(OH)2-CC was specifically associated with the nuclear chromatin fraction. This sterol remains bound to the cytosol fraction at 0°C and a dramatic movement to the nuclear chromatin occurs at 37°C indicating that the subcellular localization of the sterol is temperature dependent. Isolated intestinal cytosol, previously incubated with 1,25-(OH)2-CC, is required for transportation of the hormone to the intestinal chromatin fraction; cytosol fractions from other tissues are ineffective mediators of this sterol migration. It is concluded that the intestinal cytosol contains a specific receptor that functions to transport 1,25-(OH)2-CC to the nucleus, its probable site of action.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Mar 5 1973|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology