Table 2. CF RCI and genomic transactivation (EC50 values) in VDRwt and targeted VDR hydroxyl mutants.
| Genomic transactivation, EC50
|
|||
|---|---|---|---|
| VDR construct | RCI for CF, % | 1,25D, nM | CF, nM |
| VDRwt | 13 | 1.6 ± 1.0 (n = 23) | 5.4 ± 1.3 (n = 3) |
| S278A | 20 | 1.9 ± 0.3 (n = 5) | 0.88 ± 0.29 (n = 3) |
| Y143F/S278A | 130 ± 41 (n = 2) | 94 ± 34 (n = 3) | 1.3 ± 0.3 (n = 3) |
RCI values for CF with the indicated VDR constructs in COS-1 cells. The RCI of 1,25D is, by definition, set to 100%. The concentration of steroid producing 50% of the maximal transactivation of the osteocalcin promoter is defined as the EC50. All EC50 values shown are significantly different between 1,25D and CF with P < 0.05.