O-GlcNAc modification of nucleocytoplasmic proteins and diabetes.

Nuclear and cytosolic proteins are glycosylated on serine or threonine residues by O-linked beta-N-acetylglucosamine (O-GlcNAc). O-GlcNAc modification is one of various posttranslational modifications and seems to be involved in the modulation of transcription and signal transduction. Accumulating data suggest a role for O-GlcNAc-modified proteins in diabetes, acting as a glucose sensor. It has been suggested that the hexosamine biosynthetic pathway is involved in the mechanism causing insulin resistance and diabetic complications. Excess glucose entering into the hexosamine biosynthetic pathway might cause elevated O-GlcNAc modification of various proteins. In this article, we review the current data regarding the relationship between O-GlcNAc modification and diabetes.