O‐GlcNAcylation of the Human Kinome

Abstract

O‐GlcNAc, first characterized more than 30 years ago, is an O‐linked β‐N‐acetylglucosamine moiety attached to the side chain hydroxyl of a serine or threonine residues. O‐GlcNAc has been found on over 4,000 cytoplasmic and nuclear proteins. The addition of O‐GlcNAc to proteins is catalyzed by O‐GlcNAc transferase (OGT), while its removal is catalyzed by O‐linked N‐acetyl‐β‐D‐glucosaminidase (OGA). This dynamic and reversible modification is emerging as a key regulator of various cellular processes, such as signal transduction, transcription, cell cycle progression and protein‐protein interactions. O‐GlcNAc plays important roles in human diseases, such as cancer, diabetes and neurological disorders.Protein phosphorylation is a post‐translational modification that serves as a rapid and reversible means to modulate protein activity and transduce signals. The regulation of phosphorylation is a central mechanism in cell health and disease. O‐GlcNAcylation has extensive interplay with phosphorylation at the site level on proteins and by modifying kinases. However, the roles of O‐GlcNAcylation have only been studied on a few kinases.In vitro O‐GlcNAcylation of large kinase microarrays indicates that well over one‐half of all human protein kinases are substrates for OGT. Multiplexed kinase inhibitor beads (MIBs) are being used to confirm the O‐GlcNAcylation of kinases in vivo. These affinity beads have enriched at‐least 117 kinases as determined by mass spectrometry and HCD and ETD fragmentation are being used to map their O‐GlcNAcylation sites.Support or Funding InformationSupported by NIH P01HL107153. Dr. Hart receives a share of royalty received by the university on sales of the CTD 110.6 antibody, which are managed by JHU