First Author | Jiang MS | Year | 1997 |
Journal | J Biol Chem | Volume | 272 |
Issue | 4 | Pages | 2421-8 |
PubMed ID | 8999954 | Mgi Jnum | J:38668 |
Mgi Id | MGI:86051 | Doi | 10.1074/jbc.272.4.2421 |
Citation | Jiang MS, et al. (1997) A subpopulation of estrogen receptors are modified by O-linked N-acetylglucosamine. J Biol Chem 272(4):2421-8 |
abstractText | 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. |