FIGURE 8.

Interaction between PR-B and MAGE-11 up-regulates FKBP5 progesterone response region. A, p5M-PR-B and -A (0.5 μg) were expressed with 1 μg of pCMV-FLAG empty vector or 1 μg of pCMV-FLAG-MAGE in COS cells. The day after transfection, cells were incubated for 24 h in serum-free, phenol red-free medium with and without 10 nm progesterone and 50 ng/ml EGF. Immunoprecipitates (IP) and cell extracts (30 μg of protein/lane) were probed on the transblot using FLAG and PR sc-7208 antibodies. B, pCMV5 empty vector (−) and p5M-PR-B and -A (6 μg) were expressed in COS cells incubated for 24 h in serum-free, phenol red-free medium in the absence of progesterone. Cell extracts (40 μg of protein/lane) were probed on the transblot using PR sc-7208 antibody. C–F, p5M-PR-B and p5M-PR-A (25 ng) were expressed in CV1 cells with 4 μg of pIE2-Luc FKBP5 luciferase reporter vector and the following DNAs: 0.5 μg of pSG5 empty vector (−) and pSG5-MAGE in cells incubated with and without 1 nm progesterone (C); 0.5 μg of pSG5 (−) and pSG5-MAGE in cells incubated with or without 0.01–10 nm progesterone (D); 1.25 μg of pSG5 (−), 1 μg of pSG5-TIF2 (T), and 0.25 μg of pSG5-MAGE (M) in cells incubated with and without 1 nm progesterone (E); and 0.6 μg of pSG5, 0.1 μg of pSG5-MAGE (M), and/or 0.5 μg of pSG5-HA-p300 (P) in cells incubated with and without 1 nm progesterone (F). Luciferase activity (mean ± S.E.) is representative of three independent experiments. Error bars, S.E.