Relationship of Structure and Function of DNA-Binding Domain in Vitamin D Receptor

Molecules

Lin-Yan Wan¹  Yan-Qiong Zhang¹  Meng-Di Chen¹  Chang-Bai Liu¹  Jiang-Feng Wu¹ 

[1] Medical College, China Three Gorges University, 8 Daxue Road, Xiling District, Yichang 443002, China; E-Mails:

关键词: VDR DBD;    zinc finger structure;    CTE;    VDRE;    nVDRE;   

DOI  :  10.3390/molecules200712389

来源: mdpi

【 摘 要 】

While the structure of the DNA-binding domain (DBD) of the vitamin D receptor (VDR) has been determined in great detail, the roles of its domains and how to bind the motif of its target genes are still under debate. The VDR DBD consists of two zinc finger modules and a C-terminal extension (CTE), at the end of the C-terminal of each structure presenting α-helix. For the first zinc finger structure, N37 and S-box take part in forming a dimer with 9-cis retinoid X receptor (RXR), while V26, R50, P-box and S-box participate in binding with VDR response elements (VDRE). For the second zinc finger structure, P61, F62 and H75 are essential in the structure of the VDR homodimer with the residues N37, E92 and F93 of the downstream of partner VDR, which form the inter-DBD interface. T-box of the CTE, especially the F93 and I94, plays a critical role in heterodimerization and heterodimers–VDRE binding. Six essential residues (R102, K103, M106, I107, K109, and R110) of the CTE α-helix of VDR construct one interaction face, which packs against the DBD core of the adjacent symmetry mate. In 1,25(OH)₂D₃-activated signaling, the VDR-RXR heterodimer may bind to DR3-type VDRE and ER9-type VDREs of its target gene directly resulting in transactivation and also bind to DR3-liked nVDRE of its target gene directly resulting in transrepression. Except for this, 1α,25(OH)₂D₃ ligand VDR-RXR may bind to 1αnVDRE indirectly through VDIR, resulting in transrepression of the target gene. Upon binding of 1α,25(OH)₂D₃, VDR can transactivate and transrepress its target genes depending on the DNA motif that DBD binds.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.