O-GlcNAc modification modulates the expression of osteocalcin via OSE2 and Runx2

• Published in: Biochemical and biophysical research communications Vol. 362; no. 2; pp. 325 - 329
• Main Authors: Kim, Sun-Hee, Kim, Yun-Hee, Song, Minseok, An, Sang Hee, Byun, Ha-Young, Heo, Kyun, Lim, Seyoung, Oh, Young-Seok, Ryu, Sung Ho, Suh, Pann-Ghill
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.10.2007
• Subjects: 3T3 Cells; Acetylglucosamine - analogs & derivatives; Acetylglucosamine - metabolism; Acetylglucosamine - pharmacology; Animals; Ascorbic Acid - pharmacology; beta-N-Acetylhexosaminidases - antagonists & inhibitors; Binding Sites - genetics; Blotting, Western; Cell Differentiation - drug effects; Cercopithecus aethiops; Core Binding Factor Alpha 1 Subunit - genetics; Core Binding Factor Alpha 1 Subunit - metabolism; COS Cells; Gene Expression Regulation - drug effects; Luciferases - genetics; Luciferases - metabolism; Mice; O-GlcNAc; OSE2; Osteoblast; Osteoblasts - cytology; Osteoblasts - drug effects; Osteoblasts - metabolism; Osteocalcin; Osteocalcin - genetics; Osteocalcin - metabolism; Oximes - pharmacology; Phenylcarbamates - pharmacology; Promoter Regions, Genetic - genetics; Protein Binding; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Runx2; Transfection; Osteoblast; Osteocalcin; OSE2; O-GlcNAc; Runx2
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2007.07.149

O-Linked β- N-acetylglucosamine ( O-GlcNAc) modification, a reversible post-translational modification, has been implicated in the regulation of protein stability, subcellular localization of proteins and protein–protein interaction. Here, we demonstrate that O-GlcNAc modification regulates the expression of osteocalcin, an osteoblast-specific marker, via Runx2 transcriptional activity in osteoblastic differentiation. Protein-associated O-GlcNAc was increased during osteoblastic differentiation in MC3T3-E1 preosteoblasts. In addition, PUGNAc, an inhibitor of O-GlcNAcase, potentiated the expression of osteocalcin caused by ascorbic acid, parathyroid hormone (PTH) and forskolin. By conducting activity assays of the osteocalcin promoter and transcription factor, we found that the OSE2 site in the osteocalcin promoter and Runx2 were important for increased osteocalcin promoter activity by PUGNAc. Furthermore, PUGNAc led to increased O-GlcNAc modification of Runx2, which regulated the transcription of its target gene osteocalcin. Thus, these data provide evidence that O-GlcNAc modification may be a new mode of osteoblastic differentiation regulation.