title: MAP Kinase-Dependent RUNX2 Phosphorylation Is Necessary for Epigenetic Modification of Chromatin During Osteoblast Differentiation.
abstract: RUNX2, an essential transcription factor for osteoblast differentiation and bone formation is activated by ERK/MAP kinase-dependent phosphorylation. However, relationship between these early events and specific epigenetic modifications of chromatin during osteoblast differentiation have not been previously examined. Here, we explore these relationships using chromatin immunoprecipitation (ChIP) to detect chromatin modifications in RUNX2-binding regions of Bglap2 and Ibsp. Growth of MC3T3-E1c4 preosteoblast cells in differentiation conditions rapidly induced Bglap2 and lbsp mRNAs. For both genes, osteogenic stimulation increased chromatin-bound P-ERK, P-RUNX2, p300, and RNA polymerase II as well as histone H3K9 and H4K5 acetylation. The level of H3K4 di-methylation, another gene activation-associated histone mark, also increased. In contrast, levels of the gene repressive marks, H3K9 mono-, di-, and tri-methylation in the same regions were reduced. Inhibition of MAP kinase signaling blocked differentiation-dependent chromatin modifications and Bglap2 and Ibsp expression. To evaluate the role of RUNX2 phosphorylation in these responses, RUNX2-deficient C3H10T1/2 cells were transduced with adenovirus encoding wild type or phosphorylation site mutant RUNX2 (RUNX2 S301A/S319A). Wild type RUNX2, but not the non-phosphorylated mutant, increased H3K9 and H4K5 acetylation as well as chromatin-associated P-ERK, p300, and polymerase II. Thus, RUNX2 phosphorylation is necessary for subsequent epigenetic changes required for osteoblast gene expression. Taken together, this study reveals a molecular mechanism through which osteogenic genes are controlled by a MAPK and P-RUNX2-dependent process involving epigenetic modifications of specific promoter regions. J. Cell. Physiol. 232: 2427-2435, 2017. © 2016 Wiley Periodicals, Inc.
authors: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan.
authors: Yan
authors: Y
authors: Li
authors: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan.
authors: Chunxi
authors: C
authors: Ge
authors: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan.|Department of Biological Chemistry, University of Michigan School of Medicine, Ann Arbor, Michigan.|Department of Biomedical Engineering, University of Michigan School of Engineering, Ann Arbor, Michigan.
authors: Renny T
authors: RT
authors: Franceschi
mesh_terms: D016475:3T3 Cells; D000107:Acetylation; D000818:Animals; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D042002:Chromatin Assembly and Disassembly; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005786:Gene Expression Regulation; D006657:Histones / Q000378:metabolism; D058574:Integrin-Binding Sialoprotein / Q000235:genetics / Q000378:metabolism; D008745:Methylation; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009154:Mutation; D010006:Osteoblasts / Q000201:enzymology*; D010012:Osteogenesis / Q000235:genetics; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013997:Time Factors; D014162:Transfection
chemical_list: D002135:Calcium-Binding Proteins; D050659:Core Binding Factor Alpha 1 Subunit; D006657:Histones; C546872:Ibsp protein, mouse; D058574:Integrin-Binding Sialoprotein; D012333:RNA, Messenger; C493716:Runx2 protein, mouse; D020928:Mitogen-Activated Protein Kinases; D012319:RNA Polymerase II