O-Glcnacylation: Nutrient Sensor That Regulates Cell Physiology

O-GlcNAcylation, which is the cycling of N-acetylglucosamine (GlcNAc) on nuclear and cytosolic proteins, has extensive cross talk with phosphorylation to serve as a nutrient sensor that regulates nearly all aspects of cellular metabolism. O-GlcNAc cycling is tightly regulated by only two gene products, O-GlcNAc transferase and O-GlcNAcase that are targeted to substrates by a multitude of binding partners. Research over the past three decades has shown that O-GlcNAcylation is fundamentally important in regulating transcription, modulating signaling pathways, andmodifying the activities ofmetabolic enzymes and kinases in response to nutrients.