Title

Phosphorylation at serine 208 of the 1alpha,25-dihydroxy Vitamin D3 receptor modulates the interaction with transcriptional coactivators

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cell Biology

Date

3-21-2007

Document Type

Article

Medical Subject Headings

Mutation; Phosphoserine; Protein Binding; Receptors, Calcitriol; Trans-Activators

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

Upon ligand binding the 1alpha,25-dihydroxy Vitamin D3 receptor (VDR) undergoes a conformational change that allows interaction with coactivator proteins including p160/SRC family members and the multimeric DRIP complex through the DRIP205 subunit. Casein kinase II (CKII) phosphorylates VDR both in vitro and in vivo at serine 208 within the hinge domain. This phosphorylation does not affect the ability of VDR to bind DNA, but increases its ability to transactivate target promoters. Here, we have analyzed whether phosphorylation of VDR by CKII modulates the ability of VDR to interact with coactivators in vitro. We find that both mutation of serine 208 to aspartic acid (VDRS208D) or phosphorylation of VDR by CKII enhance the interaction of VDR with DRIP205 in the presence of 1alpha,25-dihydroxy Vitamin D3. We also find that the mutation VDRS208D neither affects the ability of this protein to bind DNA nor to interact with SRC-1 and RXRalpha. Together, our results indicate that phosphorylation of VDR at serine 208 contributes to modulate the affinity of VDR for the DRIP complex and therefore may have a role in vivo regulating VDR-mediated transcriptional enhancement.

Rights and Permissions

Citation: J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):425-9. Link to article on publisher's site

Related Resources

Link to article in PubMed