Fig. 1

Kaempferol and quercetin bind NR4A1 and inhibit NR4A1-dependent transactivation. A Structures of kaempferol and quercetin. Different concentrations of kaempferol (B) and quercetin (C) were incubated with the ligand binding domain (LBD) of NR4A1 and binding was determined in fluorescent quenching direct binding or a competitive displacement (of bis-ANS) assay as outlined in the Materials and methods. Rh30 and Rh41 cells were transfected with D UAS-luc/Gal4-NR4A1 or E an NBRE-luc/flag-NR4A1 constructs and after treatment with kaempferol (K) or quercetin (Q) for 24 h, luciferase activity was determined and normalized to the DMSO values as outlined in the Materials and methods. Results are expressed as means ± SD for at least 3 replicated determinations and significant (p < 0.05) inhibition is indicated (*)