1Alpha,25(OH)2D3-induced transrepression by vitamin D receptor through E-box-type elements in the human parathyroid hormone gene promoter

Mol Endocrinol. 2007 Feb;21(2):334-42. doi: 10.1210/me.2006-0231. Epub 2006 Nov 9.

Abstract

Although transactivation by the liganded vitamin D receptor (VDR) is well described at the molecular level, the precise molecular mechanism of negative regulation by the liganded VDR remains to be elucidated. We have previously reported a novel class of negative vitamin D response element (nVDRE) called 1alphanVDRE in the human 25(OH)D31alpha-hydroxylase [1alpha(OH)ase] gene by 1alpha,25(OH)2D3-bound VDR. This element was composed of two E-box-type motifs that bound to VDIR for transactivation, which was attenuated by liganded VDR. Here, we explore the possible functions of VDIR and E-box motifs in the human (h) PTH and hPTHrP gene promoters. Functional mapping of the hPTH and hPTHrP promoters identified E-box-type elements acting as nVDREs in both the hPTH promoter (hPTHnVDRE; -87 to -60 bp) and in the hPTHrP promoter (hPTHrPnVDRE; -850 to -600 bp; -463 to -104 bp) in a mouse renal tubule cell line. The hPTHnVDRE alone was enough to direct ligand-induced transrepression mediated through VDR/retinoid X receptor and VDIR. Direct DNA binding of hPTHnVDRE to VDIR, but not VDR/retinoid X receptor, was observed and ligand-induced transrepression was coupled with recruitment of VDR and histone deacetylase 2 (HDAC2) to the hPTH promoter. These results suggest that negative regulation of the hPTH gene by liganded VDR is mediated by VDIR directly binding to the E-box-type nVDRE at the promoter, together with recruitment of an HDAC corepressor for ligand-induced transrepression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcitriol / pharmacology*
  • Cell Line
  • E-Box Elements*
  • Gene Expression Regulation
  • Humans
  • Mice
  • Parathyroid Hormone / genetics
  • Parathyroid Hormone / physiology*
  • Parathyroid Hormone-Related Protein / genetics
  • Parathyroid Hormone-Related Protein / physiology
  • Promoter Regions, Genetic*
  • Receptors, Calcitriol / genetics
  • Receptors, Calcitriol / metabolism*
  • Retinoid X Receptors / genetics
  • Retinoid X Receptors / metabolism
  • Vitamin D Response Element

Substances

  • PTH protein, human
  • Parathyroid Hormone
  • Parathyroid Hormone-Related Protein
  • Receptors, Calcitriol
  • Retinoid X Receptors
  • Calcitriol