earticle

영어

It has been reported that one of the downstream molecules generated from glucose is uridine diphosphate-N-acetly glucosamine(UDP-GlcNAc) via the hexoamine biopsynthetic pathway (HBP). The dynamic cycle of addition and removal of O-linked-N-acetlyglucosamine (O-GlcNAc) to Ser/Thr residues is involved in regulating nuclear and cytoplasmic proteins. Nucleocytoplasmic O-GlcNAc transferase (ncOGT) adds a single GlcNAc onto hydroxyl groups of serine and threonine residues. Interestingly, O-GlcNAc glycosylation occurs in ncOGT itself as well. O-GlcNAcylation on N-terminal domain of tetratricopeptide (TPR) repeats plays an important role in nuclear localization of ncOGT. Specific nuclear localization signals (NLS) in ncOGT has not been identified. We characterized the three amino acid motif as NLS because this motif is required for the nuclear import of non-diffusible β-galactosidase. Also, we show that ncOGT binds kayropherin α proteins, and the association between kayopherin α proteins and ncOGT is interfered by O-GlcNAcylation on TPR domain. Our finding suggests the mechanism how ncOGT can be localized in the nucleus and cytosol at the same time. Therefore our data may contribute to better understanding of the key enzyme of O-GlcNAc metabolism.