PRL759 and PRA759 are constitutively active. The ability of PR mutants to induce luciferase expressed under control of the PRE promoter was assessed in Cos7 cells in the presence of progesterone and 19-norprogesterone. Luciferase activity is expressed as percent of maximal induction of PRWT by progesterone. (A) Transcriptional activity of PRWT, PRL759, PRL759A722, and PRA722 in the presence of progesterone and 19-norprogesterone. (B) Transcriptional activity of PRWT, PRI759, and PRI759A722 in the presence of progesterone and 19-norprogesterone. (C) Transcriptional activity of PRWT, PRV759, and PRV759A722 in the presence of progesterone and 19-norprogesterone. (D) Transcriptional activity of PRWT, PRA759, and PRA759A722 in the presence of progesterone and 19-norprogesterone. (E) RU486 inhibits constitutive activity of PRL759 and PRA759. The ability of RU486 to inhibit PRWT, PRL759, or PRA759 induced luciferase expression from the PRE promoter was assessed in Cos-7 cells in the presence (PRWT) or absence (PRL759 or PRA759) of 10 nM progesterone. Luciferase activity is expressed as percent of maximal induction of PRWT by 10 nM progesterone. All data points represent the mean ± SEM of at least nine independent transfections. *, P < 0.001 vs. GRWT...., P < 0.01 vs. GRWT; ‡, P < 0.05 vs. GRWT.