Chromatin remodeling and transcriptional activity of the bone-specific osteocalcin gene require CCAAT/enhancer-binding protein beta-dependent recruitment of SWI/SNF activity
Authors
Villagra, AlejandroCruzat, Fernando
Carvallo, Loreto
Paredes, Roberto
Olate, Juan
Van Wijnen, Andre J.
Stein, Gary S.
Lian, Jane B.
Stein, Janet L.
Imbalzano, Anthony N.
Montecino, Martin A.
UMass Chan Affiliations
Department of Cell BiologyDepartamento de Bioquimica y Biologia Molecular
Graduate School of Biomedical Sciences
Document Type
Journal ArticlePublication Date
2006-06-15Keywords
Animals; CCAAT-Enhancer-Binding Protein-beta; Catalytic Domain; Cholecalciferol; Chromatin; *Gene Expression Regulation; Models, Biological; Models, Genetic; Osteoblasts; Osteocalcin; Promoter Regions (Genetics); Rats; Transcription, GeneticLife Sciences
Medicine and Health Sciences
Metadata
Show full item recordAbstract
Tissue-specific activation of the osteocalcin (OC) gene is associated with changes in chromatin structure at the promoter region. Two nuclease-hypersensitive sites span the key regulatory elements that control basal tissue-specific and vitamin D3-enhanced OC gene transcription. To gain understanding of the molecular mechanisms involved in chromatin remodeling of the OC gene, we have examined the requirement for SWI/SNF activity. We inducibly expressed an ATPase-defective BRG1 catalytic subunit that forms inactive SWI/SNF complexes that bind to the OC promoter. This interaction results in inhibition of both basal and vitamin D3-enhanced OC gene transcription and a marked decrease in nuclease hypersensitivity. We find that SWI/SNF is recruited to the OC promoter via the transcription factor CCAAT/enhancer-binding protein beta, which together with Runx2 forms a stable complex to facilitate RNA polymerase II binding and activation of OC gene transcription. Together, our results indicate that the SWI/SNF complex is a key regulator of the chromatin-remodeling events that promote tissue-specific transcription in osteoblasts.Source
J Biol Chem. 2006 Aug 11;281(32):22695-706. Epub 2006 Jun 13. Link to article on publisher's siteDOI
10.1074/jbc.M511640200Permanent Link to this Item
http://hdl.handle.net/20.500.14038/32761PubMed ID
16772287Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1074/jbc.M511640200