Fig_3.tif (468.16 kB)

FKBP52 is Specifically Required for β-Catenin Potentiation of AR Activity.

figure

posted on 2015-07-24, 03:14 authored by Cheryl Storer Samaniego, Ji Ho Suh, Arundhati Chattopadhyay, Karen Olivares, Naihsuan Guy, Jeffrey C. Sivils, Prasenjit Dey, Fumiaki Yumoto, Robert J. Fletterick, Anders M. Strom, Jan-Åke Gustafsson, Paul Webb, Marc B. Cox

(A) AR-mediated luciferase assay in 52KO MEFs in the presence of the indicated transiently transfected expression plasmids with (Black bars) or without (grey bars) dihydrotestosterone (DHT). The asterisks denote a statistically significant difference (***p < 0.001; ****p < 0.0001) as compared to vector alone for each hormone condition. Hormone-dependent receptor activity in the presence FKBP52 and β-catenin also significantly differed as compared to activity in the presence of FKBP52 and β-catenin (S33A) (p < 0.001). The activity in the presence of FKBP52 and wild type or mutant β-catenin was also significantly higher in the presence of hormone than in the absence (p < 0.0001). All other conditions did not significantly differ from the vector alone control, or from each other for each hormone condition. (B) DHT-dependent activity of a Gal4-mediated luciferase reporter in the presence or absence of a Gal4-AR LBD fusion, β-catenin (S33Y) and/or FKBP52 was assessed in HeLa cells. The asterisks denote a statistically significant difference (**p < 0.01; ***p < 0.001) as compared to Gal4-AR LBD alone in the presence of DHT. Hormone-dependent Gal4-AR LBD activity in the presence of both β-catenin (S33Y) and FKBP52 was also significantly (p < 0.001) potentiated as compared to activity in the presence of either β-catenin (S33Y) or FKBP52 alone. (C) The same as in (B), except that transient, siRNA-mediated FKBP52 knockdown was assessed instead of overexpression. The asterisks denote a statistically significant difference (***p < 0.001) as compared to Gal4-AR LBD alone in the presence of DHT. Hormone-dependent Gal4-AR LBD activity in the presence of both β-catenin (S33Y) and Si-FKBP52 was also significantly (p < 0.001) reduced as comparecd to activity in the presence of β-catenin (S33Y) alone. (D) As a control for AR specificity, β-catenin (S33Y) potentiation of TCF4-mediated luciferase activity in HeLa cells was assessed in the presence or absence of FKBP52 overexpression. The asterisks denote a statistically significant (***p < 0.001) potentiation of TCF4-mediated luciferase activity as compared to all other conditions in the absence of β-catenin (S33Y). TCF4-mediated luciferase activity in the presence of β-catenin (S33Y) was not statistically (p > 0.05) different in the presence or absence of FKBP52.