T cell development and the physiological role of O-GlcNAc.

O-GlcNAcylation is an essential post-translational modification important for integrating metabolism with cell physiology. Using diverse model systems, studies of this evolutionarily conserved intracellular glycosylation have highlighted its role in stem cell maintenance, lineage specification, and disease. Although discovered over 30 years ago, the study of O-GlcNAc continues to evolve and uncover surprising roles for O-GlcNAc and the enzymes of O-GlcNAc cycling: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). In this review, using the immune system as a model of stem cell biology and cell fate determination, we discuss how O-GlcNAc is at the nexus of metabolism, proliferation, and disease.