Global Analysis of O-GlcNAc Glycoproteins in Activated Human T Cells

J Immunol. 2016 Oct 15;197(8):3086-3098. doi: 10.4049/jimmunol.1502031. Epub 2016 Sep 21.

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / metabolism
  • Animals
  • Cell Line
  • Glycoproteins / metabolism
  • Glycosylation
  • Humans
  • Lymphocyte Activation
  • Mice
  • N-Acetylglucosaminyltransferases / metabolism*
  • Protein Isoforms / metabolism
  • Protein Processing, Post-Translational
  • Proteomics
  • Receptors, Antigen, T-Cell / metabolism
  • Signal Transduction
  • T-Lymphocytes / metabolism*

Substances

  • Glycoproteins
  • Protein Isoforms
  • Receptors, Antigen, T-Cell
  • N-Acetylglucosaminyltransferases
  • UDP-N-acetylglucosamine-peptide beta-N-acetylglucosaminyltransferase
  • Acetylglucosamine