FGF-5 is a secreted member of the fibroblast growth factor (FGF) gene family which has been shown to be expressed at basal levels in the retinal pigmented epithelium (RPE) in rive. When RPE cells are stimulated to divide in rive, or cultured in vitro, FGF5 gene expression is dramatically increased. The goal of this project is to identify cis-acting sequences in the FGF-5 upstream regulatory region important in the differential regulation of FGF-5 gene expression in proliferating vs differentiated ARPE-19 cells, a human RPE cell line. We have sequenced a 1619 bp DNA fragment from the FGF-5 upstream regulatory region and subcloned it into the luciferase reporter gene vector, pGL2-Basic. A series of nested deletions from the 5-prime end was constructed and the reporter gene activity of each construct was measured in proliferating and differentiated ARPE- 19 cells. Deletion of sequences between -314 and -36 in proliferating and differentiated cells yielded very similar results, identifying this region as a (:ore enhancer/promoter region. A distal silencer/enhancer complex (-1619/-314) was identified in differentiated cells which was not apparent in proliferating cells. Heterologous reporter constructs driven by FGF5 sequences between 1256 and -883 negatively regulate expression from the SV40 core promoter in differentiated ARPE-19 cells. These results suggest that a distal element in the F(IF5 gene promoter is involved in negatively regulating its expression in differentiated ARPE-19 RPE cells.
|Original language||English (US)|
|State||Published - 1997|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology