title: Global Analysis of O-GlcNAc Glycoproteins in Activated Human T Cells.
abstract: T cell activation in response to Ag is largely regulated by protein posttranslational modifications. Although phosphorylation has been extensively characterized in T cells, much less is known about the glycosylation of serine/threonine residues by O-linked N-acetylglucosamine (O-GlcNAc). Given that O-GlcNAc appears to regulate cell signaling pathways and protein activity similarly to phosphorylation, we performed a comprehensive analysis of O-GlcNAc during T cell activation to address the functional importance of this modification and to identify the modified proteins. Activation of T cells through the TCR resulted in a global elevation of O-GlcNAc levels and in the absence of O-GlcNAc, IL-2 production and proliferation were compromised. T cell activation also led to changes in the relative expression of O-GlcNAc transferase (OGT) isoforms and accumulation of OGT at the immunological synapse of murine T cells. Using a glycoproteomics approach, we identified >200 O-GlcNAc proteins in human T cells. Many of the identified proteins had a functional relationship to RNA metabolism, and consistent with a connection between O-GlcNAc and RNA, inhibition of OGT impaired nascent RNA synthesis upon T cell activation. Overall, our studies provide a global analysis of O-GlcNAc dynamics during T cell activation and the first characterization, to our knowledge, of the O-GlcNAc glycoproteome in human T cells.
authors.affiliation: Interdepartmental Program in Immunology, Stanford University, Stanford, CA 94305.|Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305.
authors.forename: Peder J
authors.identifier: 0000-0002-2146-8724
authors.initials: PJ
authors.lastname: Lund
authors.affiliation: Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305.
authors.forename: Joshua E
authors.identifier: 0000-0002-8063-3259
authors.initials: JE
authors.lastname: Elias
authors.affiliation: Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305; mmdavis@stanford.edu.|Stanford Institute for Immunity, Transplantation, and Infection, Stanford University, Stanford, CA 94305; and.|Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305.
authors.forename: Mark M
authors.initials: MM
authors.lastname: Davis
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D006023:Glycoproteins / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D008213:Lymphocyte Activation; D051379:Mice; D017351:N-Acetylglucosaminyltransferases / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D040901:Proteomics; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D020033:Protein Isoforms; D011948:Receptors, Antigen, T-Cell; D017351:N-Acetylglucosaminyltransferases; C063057:UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase; D000117:Acetylglucosamine