Molecular characterization of the zinc finger transcription factor, Osterix.
Osterix was identified as a transcription factor expressing, in osteoblasts, required for bone formation. However, the molecular mechanisms of the gene regulation by Osterix remain elusive. In this study, we examined the transactivation property of Osterix by using the Gal4 fusion system reporter assay. We identified the transactivation domain of Osterix, which contains high proline and glycine residues and has an activation property in mammalian and yeast cells. The GST-pull down analysis revealed that the basal transcription factor, TF-IIB, but not TBP, binds to the transactivation domain. Furthermore, we found that Osterix interacts with chromatin remodeling factor, Brg-1, through its C-terminal zinc finger domain in vivo and in vitro. These findings suggest that Osterix possesses functional domains which associate with transcription mediated factors and functions as a transcriptional activator in the nucleus.
Hatta
Mitsutoki
M
Department of Oral Pathobiological Science, Hokkaido University, Sapporo, Japan.
Yoshimura
Yoshitaka
Y
Deyama
Yoshiaki
Y
Fukamizu
Akiyoshi
A
Suzuki
Kuniaki
K
D000818:Animals; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins; D000076182:Sp7 Transcription Factor; D035181:TATA-Box Binding Protein / Q000378:metabolism; D035581:Transcription Factor TFIIB / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics; D016335:Zinc Fingers
D011993:Recombinant Fusion Proteins; D000076182:Sp7 Transcription Factor; C479466:Sp7 protein, mouse; D035181:TATA-Box Binding Protein; D035581:Transcription Factor TFIIB; D014157:Transcription Factors