Linked Life Data

12145306

Source:http://linkedlifedata.com/resource/pubmed/id/12145306

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2002-9-30
pubmed:databankReference
pubmed:abstractText
We previously described an osteocalcin (OC) fibroblast growth factor (FGF) response element (FRE) DNA binding activity as a target of Msx2 transcriptional regulation. We now identify Ku70, Ku80, and Tbdn100, a variant of Tubedown-1, as constituents of the purified OCFRE-binding complex. Northern and Western blot analyses demonstrate expression of Ku and Tbdn100 in MC3T3E1 osteoblasts. FGF2 treatment regulates Ku, but not Tbdn100, protein accumulation. Gel supershift studies confirm sequence-specific DNA binding of Ku in the OCFRE complex; chromatin immunoprecipitation assays confirm association of Ku and Tbdn100 with the endogenous OC promoter. In the promoter region -154 to -113, the OCFRE is juxtaposed to OSE2, an osteoblast-specific element that binds Runx2 (Osf2, Cbfa1). Expression of the Ku.Tbdn100 complex up-regulates both the basal and Runx2-dependent transcription driven by this 42-bp OC promoter element, reconstituted in CV-1 cells. Synergistic transactivation occurs in the presence of activated FGF receptor 2 signaling. Msx2 suppresses Ku- and Runx2-dependent transcription; suppression is dependent upon the Msx2 homeodomain NH(2)-terminal arm and extension. Pull-down assays confirm physical interactions between Ku and these co-regulatory transcription factors, consistent with the functional interactions identified. Finally, cultured Ku70 -/- calvarial cells exhibit a profound, selective deficiency in OC expression as compared with wild-type calvarial cells, confirming the biochemical data showing a role for Ku in OC transcription. In toto, these data indicate that a novel Ku antigen complex assembles on the OC promoter, functioning in concert with Msx2 and Runx2 to regulate OC gene expression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37280-91
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:12145306-3T3 Cells, pubmed-meshheading:12145306-Amino Acid Sequence, pubmed-meshheading:12145306-Animals, pubmed-meshheading:12145306-Antigens, Nuclear, pubmed-meshheading:12145306-Base Sequence, pubmed-meshheading:12145306-Cell Line, pubmed-meshheading:12145306-Cell Nucleus, pubmed-meshheading:12145306-Cells, Cultured, pubmed-meshheading:12145306-DNA, Complementary, pubmed-meshheading:12145306-DNA Helicases, pubmed-meshheading:12145306-DNA-Binding Proteins, pubmed-meshheading:12145306-Fibroblast Growth Factor 2, pubmed-meshheading:12145306-Forskolin, pubmed-meshheading:12145306-Gene Expression Regulation, pubmed-meshheading:12145306-Humans, pubmed-meshheading:12145306-Mice, pubmed-meshheading:12145306-Molecular Sequence Data, pubmed-meshheading:12145306-Nuclear Proteins, pubmed-meshheading:12145306-Osteoblasts, pubmed-meshheading:12145306-Osteocalcin, pubmed-meshheading:12145306-Transcription Factors
pubmed:year
2002
pubmed:articleTitle
Regulation of osteocalcin gene expression by a novel Ku antigen transcription factor complex.
pubmed:affiliation
Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't