FIG. 7.

The GR binding site mutation in the TBLV enhancer abolishes hormone-dependent transcriptional activation but not T-cell enhancer activity. (A) Activity of the GR binding site mutant 586M in transient transfections of XC rat cells. Hormones were added as indicated 24 h after transfection using the DMRIE-C method as specified by the manufacturer. After an additional 24 h in the presence or absence of 10⁻⁶ M dexamethasone, cell extracts were prepared for reporter gene assays. (B) Activity of the GR binding site mutant in transient transfection assays of Jurkat T cells grown in the absence of exogenous steroid hormones. Luciferase (LUC) activity was determined as described in the legend to Fig. 2 except that values are relative to that for pC3H-LUC in the absence of dexamethasone (assigned a value of 1). Means of triplicate assays with standard deviations are shown.