O-GlcNAc modification modulates the expression of osteocalcin via OSE2 and Runx2.
O-Linked beta-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.
Kim
Sun-Hee
SH
Department of Life Science, Division of Molecular and Life Science, Biotech Center, Pohang University of Science and Technology, San 31 Hyoja-Dong, Nam-Gu, Pohang, Kyungbuk 790-784, Republic of Korea.
Kim
Yun-Hee
YH
Song
Minseok
M
An
Sang Hee
SH
Byun
Ha-Young
HY
Heo
Kyun
K
Lim
Seyoung
S
Oh
Young-Seok
YS
Ryu
Sung Ho
SH
Suh
Pann-Ghill
PG
D016475:3T3 Cells; D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D019556:COS Cells; D002454:Cell Differentiation / Q000187:drug effects; D002522:Chlorocebus aethiops; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics* / Q000378:metabolism; D010091:Oximes / Q000494:pharmacology; D048448:Phenylcarbamates / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D001619:beta-N-Acetylhexosaminidases / Q000037:antagonists & inhibitors
D050659:Core Binding Factor Alpha 1 Subunit; D010091:Oximes; D048448:Phenylcarbamates; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015675:Osteocalcin; C068836:N-acetylglucosaminono-1,5-lactone O-(phenylcarbamoyl)oxime; D008156:Luciferases; D001619:beta-N-Acetylhexosaminidases; D001205:Ascorbic Acid; D000117:Acetylglucosamine