Indroduction
Dendritic cell (DC) immune functions are regulated by a myriad of proteins, which themselves are regulated by various post-translational modifications (PTMs). O-GlcNAcylation of intracellular proteins has been found to control a variety of cellular processes such as transcription or signal transduction and occur through the opposing actions of the O-GlcNAc transferase (OGT) and O-GlcNAcase in a reversible and dynamic manner. Although O- GlcNAcylation is highly conserved among metazoans, little is known about the regulatory mechanisms behind this PTM.
Aim
Our research focuses on investigating O-GlcNAcylation in DCs, where this modification has not been described yet. In particular, this study aims to understand how OGT is regulated in DCs and how this single enzyme specifically recognises and controls functions of thousands of its substrates. We propose that in DCs various proteins interact with OGT acting as substrate recognition factors directing OGT to its substrates. To examine this hypothesis, we have successfully pulled down and identified OGT interaction partners in DCs from a murine DC line via affinity purification mass spectrometry.
Results
Here we present the OGT interactome of DCs, which we have analysed to understand which interactors confer substrate specificity and selectivity. Furthermore, we have found that the genetic manipulation of OGT results in the loss of numerous interactors accompanied by a change in the immunological properties of DCs, hinting towards a crucial role of these interactions. Taken together our data suggests that OGT is an integral player in DC immune functions and therefore representing a potential target for the manipulation of immune responses.