Hydrogen/Deuterium Exchange Reveals Distinct Agonist/Partial Agonist Receptor Dynamics within Vitamin D Receptor/Retinoid X Receptor Heterodimer

• Published in: Structure (London) Vol. 18; no. 10; pp. 1332 - 1341
• Main Authors: Zhang, Jun, Chalmers, Michael J., Stayrook, Keith R., Burris, Lorri L., Garcia-Ordonez, Ruben D., Pascal, Bruce D., Burris, Thomas P., Dodge, Jeffery A., Griffin, Patrick R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 13.10.2010
• Subjects: Amino Acid Sequence; Binding; Binding, Competitive; Calcitriol - agonists; Calcitriol - analogs & derivatives; Calcitriol - chemistry; Calcitriol - metabolism; Calcitriol - pharmacology; Crystal structure; Crystallography, X-Ray; Deuterium; Deuterium - chemistry; Deuterium - metabolism; Deuterium Exchange Measurement - methods; Dimers; Dynamics; HEK293 Cells; Humans; Hydrogen - chemistry; Hydrogen - metabolism; Hydroxycholecalciferols - agonists; Hydroxycholecalciferols - chemistry; Hydroxycholecalciferols - metabolism; Kinetics; Ligands; Luciferases - genetics; Luciferases - metabolism; Mass Spectrometry; Models, Molecular; Molecular Sequence Data; Protein Conformation; Protein Multimerization; Receptors; Receptors, Calcitriol - agonists; Receptors, Calcitriol - chemistry; Receptors, Calcitriol - metabolism; Retinoid X Receptors - agonists; Retinoid X Receptors - chemistry; Retinoid X Receptors - metabolism; Transcriptional Activation - drug effects; Transfection; Vitamin D - analogs & derivatives; Vitamins
• ISSN: 0969-2126; 1878-4186
• DOI: 10.1016/j.str.2010.07.007

Regulation of nuclear receptor (NR) activity is driven by alterations in the conformational dynamics of the receptor upon ligand binding. Previously, we demonstrated that hydrogen/deuterium exchange (HDX) can be applied to determine novel mechanism of action of PPARγ ligands and in predicting tissue specificity of selective estrogen receptor modulators. Here, we applied HDX to probe the conformational dynamics of the ligand binding domain (LBD) of the vitamin D receptor (VDR) upon binding its natural ligand 1α,25-dihydroxyvitamin D3 (1,25D3), and two analogs, alfacalcidol and ED-71. Comparison of HDX profiles from ligands in complex with the LBD with full-length receptor bound to its cognate receptor retinoid X receptor (RXR) revealed unique receptor dynamics that could not be inferred from static crystal structures. These results demonstrate that ligands modulate the dynamics of the heterodimer interface as well as provide insight into the role of AF-2 dynamics in the action of VDR partial agonists. ► Dynamics of apo VDR are presented for which no crystal structure is available ► HDX of 1DB1 and 2HAR show perturbation of dimer interface upon ligand binding ► HDX demonstrates the role of 25-hydroxyl group for the activation of VDR ► HDX profiles of VDR LBD and intact RXR/VDR provide insight into dimer interface