Glycosylation of the murine estrogen receptor-alpha.
O-linked N-acetylglucosamine (O-GlcNAc) is a highly dynamic and abundant modification found on nuclear and cytoplasmic proteins of nearly all eukaryotes. O-GlcNAc addition is required for life at the single cell level and is analogous to protein phosphorylation in most respects. In a previous study (M.S. Jiang, G.W. Hart, A subpopulation of estrogen receptors are modified by O-linked N-acetylglucosamine. J. Biol. Chem. 270 (1997) 2421-2428), we demonstrated that a subpopulation of the murine estrogen receptor-alpha (mER-alpha) is modified by O-GlcNAc at Thr(575). Here we mutated mER-alpha to convert Thr(575) and Ser(576) to Val and Ala, respectively. Surprisingly, this glycosylation-site mutant is still extensively modified by O-GlcNAc. Analyses of glycopeptides identified two additional sites of modification on mER-alpha, at Ser(10) and Thr(50) near the N-terminus. The major glycosylation sites are within or near PEST regions, suggesting that O-GlcNAc may regulate mER-alpha turnover.
Department of Biological Chemistry, School of Medicine, Johns Hopkins University, 725 N Wolfe St., Baltimore, MD 21205-2185, USA.
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D000117:Acetylglucosamine / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D047628:Estrogen Receptor alpha; D005700:Galactosyltransferases / Q000378:metabolism; D006031:Glycosylation; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010449:Peptide Mapping; D010455:Peptides / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D011960:Receptors, Estrogen / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014162:Transfection; D014357:Trypsin / Q000378:metabolism
D047628:Estrogen Receptor alpha; D010455:Peptides; D011960:Receptors, Estrogen; D011994:Recombinant Proteins; D005700:Galactosyltransferases; D014357:Trypsin; D000117:Acetylglucosamine