Identification of sequence elements in mouse calbindin-D28k gene that confer 1,25-dihydroxyvitamin D3- and butyrate-inducible responses.
AUTOR(ES)
Gill, R K
RESUMO
We have examined the 5' flanking region of the mouse calbindin-D28k gene and identified a 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]-responsive element by deletion mutant analysis of the native promoter as well as by studies with a heterologous thymidine kinase (TK) promoter. The segment between residues -200 and -169 was found to confer a dose-dependent 1,25-(OH)2D3 responsiveness through the TK promoter in Ros 17/2.8 cells as well as in CV-1 cells cotransfected with pAV-hVDR (human vitamin D receptor expression vector). This region contains sequences homologous to the rat osteocalcin vitamin D response element (VDRE). Incubation of this element with nuclear extracts from 1,25-(OH)2D3-treated Ros 17/2.8 cells or from 1,25-(OH)2D3-treated COS cells that had been transfected with pAV-hVDR resulted in a specific protein-DNA interaction. In addition to 1,25-(OH)2D3, sodium butyrate, a differentiating agent, has also been found to modulate expression of calbindin-D28k. Deletion analysis of the mouse calbindin-D28k promoter as well as studies with a heterologous TK promoter resulted in identification of a butyrate-responsive element between -180 and -150 that was found to bind specifically to nuclear factors from butyrate-treated Ros 17/2.8 cells. This butyrate-responsive element may represent a genetic element acted upon by enhancer binding proteins. In summary, the 5' flanking region of the mouse calbindin-D28k gene contains responsive elements that interact with nuclear factors and may mediate, at least in part, the enhanced expression of this gene by 1,25-(OH)2D3 and butyrate.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=46221Documentos Relacionados
- DNA sequences in the rat osteocalcin gene that bind the 1,25-dihydroxyvitamin D3 receptor and confer responsiveness to 1,25-dihydroxyvitamin D3.
- Expression of calbindin-D28K in motoneuron hybrid cells after retroviral infection with calbindin-D28K cDNA prevents amyotrophic lateral sclerosis IgG-mediated cytotoxicity.
- Identification of a 1,25-dihydroxyvitamin D3-response element in the 5'-flanking region of the rat calbindin D-9k gene.
- 1,25-Dihydroxyvitamin D3 up-regulates the 1,25-dihydroxyvitamin D3 receptor in vivo.
- Identification of a DNA sequence responsible for binding of the 1,25-dihydroxyvitamin D3 receptor and 1,25-dihydroxyvitamin D3 enhancement of mouse secreted phosphoprotein 1 (SPP-1 or osteopontin) gene expression.