The glucocorticoid receptor is tethered to DNA-bound Oct-1 at the mouse gonadotropin-releasing hormone distal negative glucocorticoid response element

J Biol Chem. 1999 Jan 22;274(4):2372-8. doi: 10.1074/jbc.274.4.2372.

Abstract

An element required for glucocorticoid repression of mouse gonadotropin-releasing hormone (GnRH) gene transcription, the distal negative glucocorticoid response element (nGRE), is not bound directly by glucocorticoid receptors (GRs) but is recognized by Oct-1 present in GT1-7 cell nuclear extracts or by Oct-1 purified from HeLa cells. Furthermore, purified full-length GRs interact directly with purified Oct-1 bound to the distal nGRE. Increasing the extent of distal nGRE match to an Oct-1 consensus site not only increases the affinity of Oct-1 binding, but also alters the conformation of DNA-bound Oct-1 and the pattern of protein DNA complexes formed in vitro with GT1-7 cell nuclear extracts. In addition, the interaction of purified GR with DNA-bound Oct-1 is altered when Oct-1 is bound to the consensus Oct-1 site. Mutation of the distal nGRE to a consensus Oct-1 site is also associated with reduced glucocorticoid repression in transfected GT1-7 cells. Furthermore, repression of GnRH gene transcription by 12-O-tetradecanoylphorbol-13-acetate, which utilizes sequences that overlap with the nGRE, is reversed by this distal nGRE mutation leading to activation of GnRH gene transcription. Thus, changes in the assembly of multi-protein complexes at the distal nGRE can influence the regulation of GnRH gene transcription.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • DNA-Binding Proteins / metabolism*
  • Glucocorticoids / metabolism*
  • Gonadotropin-Releasing Hormone / metabolism*
  • HeLa Cells
  • Host Cell Factor C1
  • Humans
  • Mice
  • Molecular Sequence Data
  • Octamer Transcription Factor-1
  • Promoter Regions, Genetic
  • Protein Binding
  • Receptors, Glucocorticoid / metabolism*
  • Tetradecanoylphorbol Acetate / pharmacology
  • Transcription Factors / metabolism*

Substances

  • DNA-Binding Proteins
  • Glucocorticoids
  • HCFC1 protein, human
  • Hcfc1 protein, mouse
  • Host Cell Factor C1
  • Octamer Transcription Factor-1
  • POU2F1 protein, human
  • Pou2f1 protein, mouse
  • Receptors, Glucocorticoid
  • Transcription Factors
  • Gonadotropin-Releasing Hormone
  • Tetradecanoylphorbol Acetate