Purpose. FGF-5 is a secreted member of the FGF gene family which has been shown to be expressed at basal levels in differentiated cells of the CNS. The goal of this project is to identify cu-acting sequences in the FGF-5 5' flanking region important in the differential regulation of FGF-5 gene expression in proliferating vs differentiated human ARPE-19 cells. JVlethod-. We have previously reported the subcloning and sequencing of a 1650 bp DNA fragment from the FGF-5 5' flanking region into the luciferase reporter gene vector, pGL2-Basic. Differing lipofectamine-mediated transfection conditions were optimized for proliferating and differentiated ARPE-19 cells, a human RPE cell line developed and characterized in our laboratory. A series of nested deletions from the 5' end was constructed and the reporter gene activity of each construct was measured in proliferating and differentiated ARPE-19 cells. Results. Deletion of sequences between -883 and -446 results in a 4fold decrease in luciferase activity in differentiated ARPE-19 cells. However, deletion of these same sequences in proliferating cells results in a 3-fold increase in luciferase gene expression. Conclusions. A 437 bp DNA fragment between -883 and -446 within the FGF-5 gene promoter can function as either a positive or negative regulatory element in ARPE-19 cells depending upon the cellular context. Consensus sites for several differentiation-specific trans-acting factors map to this region, including LyF-1, Dc-2, and GATA 1-3.
|Original language||English (US)|
|Journal||Investigative Ophthalmology and Visual Science|
|State||Published - 1997|
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