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.
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Authors | M S Jiang, G W Hart |
Journal | The Journal of biological chemistry
(J Biol Chem)
Vol. 272
Issue 4
Pg. 2421-8
(Jan 24 1997)
ISSN: 0021-9258 [Print] United States |
PMID | 8999954
(Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Receptors, Estrogen
- Acetylglucosamine
- Galactose
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Topics |
- 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
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