title: Cysteine S-linked N-acetylglucosamine (S-GlcNAcylation), A New Post-translational Modification in Mammals.
abstract: Intracellular GlcNAcylation of Ser and Thr residues is a well-known and widely investigated post-translational modification. This post-translational modification has been shown to play a significant role in cell signaling and in many regulatory processes within cells. O-GlcNAc transferase is the enzyme responsible for glycosylating cytosolic and nuclear proteins with a single GlcNAc residue on Ser and Thr side-chains. Here we report that the same enzyme may also be responsible for S-GlcNAcylation, i.e. for linking the GlcNAc unit to the peptide by modifying a cysteine side-chain. We also report that O-GlcNAcase, the enzyme responsible for removal of O-GlcNAcylation does not appear to remove the S-linked sugar. Such Cys modifications have been detected and identified in mouse and rat samples. This work has established the occurrence of 14 modification sites assigned to 11 proteins unambiguously. We have also identified S-GlcNAcylation from human Host Cell Factor 1 isolated from HEK-cells. Although these site assignments are primarily based on electron-transfer dissociation mass spectra, we also report that S-linked GlcNAc is more stable under collisional activation than O-linked GlcNAc derivatives.
authors: From the ‡Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, 600 16th Street Genentech Hall, N472, Box 2240, San Francisco, California 94158-2517.
authors: Jason C
authors: JC
authors: Maynard
authors: From the ‡Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, 600 16th Street Genentech Hall, N472, Box 2240, San Francisco, California 94158-2517.
authors: Alma L
authors: AL
authors: Burlingame
authors: From the ‡Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, 600 16th Street Genentech Hall, N472, Box 2240, San Francisco, California 94158-2517 folkl@cgl.ucsf.edu.
authors: Katalin F
authors: KF
authors: Medzihradszky
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry*; D000818:Animals; D003545:Cysteine / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry*; D057809:HEK293 Cells; D051863:Host Cell Factor C1 / Q000737:chemistry; D006801:Humans; D013058:Mass Spectrometry; D051379:Mice; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats
chemical_list: D006020:Glycopeptides; C497692:HCFC1 protein, human; D051863:Host Cell Factor C1; D017351:N-Acetylglucosaminyltransferases; C449880:O-GlcNAc transferase; D003545:Cysteine; D000117:Acetylglucosamine