title: Identification of the GATA factor TRPS1 as a repressor of the osteocalcin promoter.
abstract: A proteomic analysis of proteins bound to the osteocalcin OSE2 sequence of the mouse osteocalcin promoter identified TRPS1 as a regulator of osteocalcin transcription. Mutations in the TRPS1 gene are responsible for human tricho-rhino-phalangeal syndrome, which is characterized by skeletal and craniofacial abnormalities. TRPS1 has been shown to bind regulatory promoter sequences containing GATA consensus binding sites and to repress transcription of genes involved in chondrocyte differentiation. Here we show that TRPS1 can directly bind the osteocalcin promoter in the presence or absence of Runx2. TRPS1 binds through a GATA binding sequence in the proximal promoter of the osteocalcin gene. The GATA binding site is conserved in mice, humans, and rats, although its location and orientation are not. Mutation of the mouse or human GATA binding sequence abrogates binding of TRPS1 to the osteocalcin promoter. We show that TRPS1 is expressed in osteosarcoma cells and upon induction of osteoblast differentiation in primary mouse bone marrow stromal cells and that TRPS1 regulates the expression of osteocalcin in both cell types. The expression of TRPS1 modulates mineralized bone matrix formation in differentiating osteoblast cells. These data suggest a role for TRPS1 in osteoblast differentiation, in addition to its previously described role in chondrogenesis.
authors.affiliation: Department of Cell and Tissue Biology, Programs in Cell Biology and Developmental Biology, University of California, San Francisco, California 94143, USA.
authors.forename: Denise M
authors.initials: DM
authors.lastname: Piscopo
authors.forename: Eric B
authors.initials: EB
authors.lastname: Johansen
authors.forename: Rik
authors.initials: R
authors.lastname: Derynck
mesh_terms: D000728:Androgens / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D050071:Bone Density Conservation Agents / Q000494:pharmacology; D001853:Bone Marrow / Q000187:drug effects / Q000378:metabolism; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002113:Calcification, Physiologic / Q000187:drug effects; D002454:Cell Differentiation; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000494:pharmacology; D047369:Chromatin Immunoprecipitation; D002853:Chromatography, Liquid; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D050980:GATA Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D047468:Immunoprecipitation; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D010006:Osteoblasts / Q000378:metabolism; D015675:Osteocalcin / Q000235:genetics*; D012516:Osteosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D000728:Androgens; D050071:Bone Density Conservation Agents; D050659:Core Binding Factor Alpha 1 Subunit; D017931:DNA Primers; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D050980:GATA Transcription Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012097:Repressor Proteins; C108387:TRPS1 protein, human; D014157:Transcription Factors; C525953:Trps1 protein, mouse; D015675:Osteocalcin; D002762:Cholecalciferol; D008156:Luciferases