Site-specific interplay between O-GlcNAcylation and phosphorylation in cellular regulation

Abstract 

Ser(Thr)-O-linked β-N-acetylglucosamine (O-GlcNAc) is a ubiquitous modification of nucleocytoplasmic proteins. Extensive crosstalk exists between O-GlcNAcylation and phosphorylation, which regulates signaling in response to nutrients/stress. The development of novel O-GlcNAc detection and enrichment methods has improved our understanding of O-GlcNAc functions. Mass spectrometry has revealed O-GlcNAc’s many interactions with phosphorylation-mediated signaling. However, mechanisms regulating O-GlcNAcylation and phosphorylation are quite different. Phosphorylation is catalyzed by hundreds of distinct kinases. In contrast, in mammals, uridine diphospho-N-acetylglucosamine:polypeptide β-N-acetylglucosaminyl transferase (OGT) and β-D-N-acetylglucosaminidase (OGA) are encoded by single highly conserved genes. Both OGT’s and OGA’s specificities are determined by their transient associations with many other proteins to create a multitude of specific holoenzymes. The extensive crosstalk between O-GlcNAcylation and phosphorylation represents a new paradigm for cellular signaling.

Abbreviations: O-GlcNAc, O-linked β-N-acetylglucosamine, OGT, uridine diphospho-N-acetylglucosamine:polypeptide β-N-acetylglucosaminyl transferase, RNAP II, RNA polymerase II, OGA, β-D-N-acetylglucosaminidase, PTM, posttranslational modification, UDP-GlcNAc, uridine diphospho-N-acetylglucosamine, ES, embryonic stem, kDa, kilodalton, TPR, tetratricopeptide repeats, hOGA, human OGA, HAT, histone acetyltransferase, HBP, hexosamine biosynthetic pathway, ATP, adenosine triphosphate, GFAT, l-glutamine:d-fructose-6-phosphate aminotransferase, IRS1, insulin receptor substrate 1, RNAi, RNA interference, PUGNAc, O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino-N-phenylcarbamate, Hsp, heat shock protein, AMPK, AMP-activated protein kinase, MAPK, mitogen activated protein kinase, sWGA, succinylated Wheat-Germ Agglutinin, CTD, carboxyl terminal domain, CID, collision induced dissociation, CAD, collision activated dissociation, ECD, electron capture dissociation, ETD, electron transfer dissociation, GalT, galactosyltransferse, RP-HPLC, reverse phase high performance liquid chromatography, NF, neurofilament, ER, estrogen receptor, TAS, tagging-via-substrate, UDP-GlcNAz, UDP-N-azidoacetylglucosamine, DTT, dithiothreitol, BEMAD, β-elimination followed by Michael Addition with DTT, CaMKIV, calcium/calmodulin-dependent kinase IV, PC-biotin, photocleavable biotin, FT-ICR, Fourier transform ion cyclotron resonance, FoxO1, Forkhead box O1, PGC-1α, peroxisome proliferator activated receptor γ coactivator-1α, SILAC, stable isotope labeling with amino acids in cell culture, GSK, glycogen synthase kinase, iTRAQ, isobaric tags for relative and absolute quantification, TMT, tandem mass tags, QUIC-tag, quantitative isotopic and chemoenzymatic tag, OA, okadaic acid, PKA, protein kinase A, AD, Alzheimer’s disease, PHF-tau, paired helical filamentous tau, TMG, Thiamet G, eNOS, endothelial nitric oxide synthase, PEST, Pro, Glu, Ser and Thr, IKKβ, Iκ kinase β, PIP3, phosphatidylinositol 3,4,5-triphosphate, TAFII110, TATA-binding protein-associated factor, TFIID, transcription factor II D, GABA, gamma-aminobutyric acid, GRIF, GABA_A receptor-associated protein, MYPT1, myosin phosphatase targeting subunit 1, CARM1, coactivator-associated arginine methyltransferase1

Keywords: O-GlcNAcylation, Phosphorylation, OGT, OGA, Signaling, Mass spectrometry, O-GlcNAc