Alternative O-glycosylation/O-phosphorylation of the murine estrogen receptor beta

Biochemistry. 2000 Sep 26;39(38):11609-20. doi: 10.1021/bi000755i.

Abstract

Estrogen receptor beta, a homologue to estrogen receptor alpha, is a new member of the steroid hormone receptor family. Recently, we documented that estrogen receptor alpha, like other transcription factors, is modified by O-linked N-acetylglucosamine (O-GlcNAc), a ubiquitous transitory posttranslational modification on nuclear and cytoplasmic proteins. Here, we report that estrogen receptor beta is alternatively modified by either O-GlcNAc or O-phosphate. Lectin chromatography of in vitro translated protein first suggested that murine estrogen receptor beta (mER-beta) is O-GlcNAcylated. Structural characterization of the carbohydrate moieties on mER-beta, overexpressed in insect Sf9 cells, confirmed the presence of O-GlcNAc. mER-beta, overexpressed in mammalian cells, is also O-GlcNAcylated. The major site of O-GlcNAc on mER-beta from Sf9 cells is Ser(16) near the N-terminus. Concomitant analyses also documented the O-phosphorylation of mER-beta at Ser(16). MALDI-TOF mass spectrometry showed alternative occupancy of this locus by these two abundant and dynamic posttranslational modifications. The localization of a major O-GlcNAc/O-phosphate site in proximity of the transactivation domain and as part of a PEST region (target sequences for rapid protein degradation) on mER-beta suggests that these modifications may play a role in regulating estrogen receptor beta transactivation and turnover.

Publication types

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

MeSH terms

  • Acetylglucosamine / isolation & purification
  • Acetylglucosamine / metabolism
  • Acylation
  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Carbohydrate Conformation
  • Estrogen Receptor beta
  • Glycosylation
  • Mice
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Phosphorylation
  • Protein Structure, Tertiary / genetics
  • Receptors, Estrogen / biosynthesis
  • Receptors, Estrogen / chemistry*
  • Receptors, Estrogen / genetics
  • Receptors, Estrogen / metabolism*
  • Serine / genetics
  • Serine / metabolism
  • Spodoptera / genetics
  • Transcriptional Activation

Substances

  • Estrogen Receptor beta
  • Peptide Fragments
  • Receptors, Estrogen
  • Serine
  • Acetylglucosamine