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Identification of Osteoblast Proteins O‐GlcNAc Modified During Osteogenesis
Author(s) -
Nagel Alexis K,
Schilling Michael,
Berkaw Mary,
Ball Lauren E
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.827.1
Subject(s) - runx2 , chemistry , osteoblast , forskolin , extracellular matrix , alkaline phosphatase , mesenchymal stem cell , parathyroid hormone , extracellular , microbiology and biotechnology , signal transduction , downregulation and upregulation , enzyme , biochemistry , gene , biology , receptor , calcium , in vitro , organic chemistry
The nutrient responsive O‐GlcNAc post‐translational modification (PTM) modulates signaling and transcriptional pathways contributing to cellular development and survival. Supporting a role for this PTM in osteoblasts (OB), parathyroid hormone‐or forskolin‐induced RUNX2 activity is enhanced in murine MC3T3E1 preOB in the presence of the β‐N‐acetyl‐D‐glucosamindase inhibitor PUGNAc. In this study we employed lectin weak affinity chromatography (LWAC) to facilitate the identification of O‐GlcNAcylated OB proteins by C18 nLC‐MS/ MS with CID/ETD fragmentation (LTQ‐XL). Twenty O‐GlcNAc modified peptides from 18 total proteins were elucidated in in 7‐day differentiated MC3T3E1s. Seventeen sites of O‐GlcNAc modification were unambiguously mapped, including 5 novel sites of O‐GlcNAc modification on TAB2, SBNO1, UBAP2l, LPP, and CBP. Both expression and activity of alkaline phosphatase (ALP), an intermediate marker of extracellular matrix maturation, were significantly enhanced in bone marrow mesenchymal stem cells cultured under osteogenic conditions for 6 days in the presence of Thiamet G, a specific inhibitor of OGA. These data provide the first evidence that O‐GlcNAc signaling can modulate extracellular matrix maturation during osteogenesis. Future studies will focus on pathways regulated by O‐GlcNAc in OB. This work is supported by NIH/NIDCR grant nos. RO1‐DE020925–01A1 and T32‐DE017551–05.