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Published on: June 27, 2017
Hunchback sequence binding protein suppresses mouse TGF-beta3 promoter in vitro
Kiyomi Yamazaki1, David L Crowe, Charles F Shuler
1Center for Craniofacial Molecular Biology, School of Dentistry, University of Southern California, Los Angeles, CA, USA.
Biochemical and Biophysical Research Communications
|June 20, 2006
Summary
Researchers identified a specific DNA sequence in the transforming growth factor-beta3 (TGF-beta3) gene promoter that binds hunchback sequence binding protein (HbSBP). This binding suppresses TGF-beta3 gene activity in melanoma cells, suggesting cell-specific transcriptional regulation.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- Transforming growth factor-beta3 (TGF-beta3) plays a crucial role in embryonic development and tissue-specific gene expression.
- Understanding the transcriptional regulation of TGF-beta3 is essential for deciphering its biological functions.
Purpose of the Study:
- To clone and sequence the mouse TGF-beta3 5'-flanking region.
- To investigate the transcriptional regulation of the TGF-beta3 gene, particularly in melanoma cells.
Main Methods:
- Cloning of promoter fragments into a luciferase reporter plasmid.
- Functional analysis in human skin melanoma A375 cells.
- Electrophoretic mobility shift assay (EMSA) and Western blot analysis to detect protein binding and expression.
Main Results:
- A 1.8 kb fragment of the TGF-beta3 5'-flanking region showed high promoter activity.
- A functional hunchback-binding site within this region was identified, which suppresses TGF-beta3 promoter activity.
- Hunchback sequence binding protein (HbSBP) was found to be responsible for this suppression and showed cell-type-specific expression, absent in fibroblasts and other melanoma cells.
Conclusions:
- The hunchback-binding site and HbSBP are key regulators of TGF-beta3 gene transcription.
- HbSBP exhibits cell-type-specific expression, indicating a specialized role in TGF-beta3 regulation in certain cell lineages like A375 melanoma cells.
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