A subpopulation of estrogen receptors are modified by O-linked N-acetylglucosamine

J Biol Chem. 1997 Jan 24;272(4):2421-8. doi: 10.1074/jbc.272.4.2421.

Abstract

Estrogen receptors (ER) are ligand-inducible transcription factors regulated by Ser(Thr)-O-phosphorylation. Many transcription factors and eukaryotic RNA polymerase II itself are also dynamically modified by Ser(Thr)-O-linked N-acetylglucosamine moieties (O-GlcNAc). Here we report that subpopulations of murine, bovine, and human estrogen receptors are modified by O-GlcNAc. O-GlcNAc moieties were detected on insect cell-expressed, mouse ER (mER) by probing with bovine milk galactosyltransferase, followed by structural analysis. Wheat germ agglutinin-Sepharose affinity chromatography also readily detected terminal GlcNAc residues on subpopulations of ER purified from calf uterus, from human breast cancer cells (MCF-7), or from mER produced by in vitro translation. These data suggest that greater than 10% of these populations of estrogen receptors bear O-GlcNAc. Site mapping of insect cell expressed mER localized one major site of O-GlcNAc addition to Thr-575, within a PEST region of the carboxyl-terminal F domain. Based upon their relative resistance to both hexosaminidase and to in vitro galactosylation, O-GlcNAc moieties appear to be largely buried on native mER. This dynamic saccharide modification, like phosphorylation, may play a role in modulating the dimerization, stability, or transactivation functions of estrogen receptors.

Publication types

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

MeSH terms

  • Acetylglucosamine / metabolism*
  • Amino Acid Sequence
  • Animals
  • Cattle
  • Chromatography, Affinity
  • Chromatography, Gel
  • Chromatography, High Pressure Liquid
  • Female
  • Galactose / metabolism
  • Humans
  • Mice
  • Molecular Sequence Data
  • Receptors, Estrogen / metabolism*
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Receptors, Estrogen
  • Acetylglucosamine
  • Galactose