Fig. 8
From: Defining a conformational ensemble that directs activation of PPARγ
Heterodimerization of PPARγ LBD with RXRα LBD favors coactivator binding. a 19F NMR of PPARγK502C-BTFA bound to T0070907 and PPARγC313A,502C-BTFA bound to MRL24 or GW1929 or with no ligand bound was performed in the presence (orange) or absence (black) of RXRα LBD. These experiments were performed once. d The 19F NMR signal from the MRL24 ligand. Broadening and consequent reduction in signal intensity is expected as a consequence of the increased rotational correlation time of the heterodimer complex. b, c TR-FRET was used to measure interaction between wt PPARγ LBD and MED1 or NCoR in the presence or absence of equimolar concentrations of RXRα. Error bars represent standard deviation of two technical replicates within a single experiment. The experiment was repeated twice and gave similar results each time. e Heterodimerization favors MED1 binding (p = 0.0017) and disfavors NCoR binding (p = 0.0076) to apo PPARγ. In addition, visual and statistical comparison of NCoR and MED1 recruitment to PPARγ LBD saturated with ligand (four highest concentrations of ligands) indicates that RXRα affects co-regulator recruitment to T0070907-bound PPARγ (NCoR, p = 0.0042; MED1, p = 0.0027) more than GW1929 (NCoR, p = 0.44; MED1, p = 0.34) or MRL24 (NCoR, p = 0.0141; MED1, p = 0.061). All p values are derived from a two-tailed t test
