NFY transcription factor binds to regulatory element AIC and transactivates the human apolipoprotein A-I promoter in HEPG2 cells.

Previous studies have shown that the regulatory element AIC of apolipoprotein A-I is recognized by both positive and negative regulators which bind to over-lapping domains. One of these activities has been designated AIC1. Competition experiments showed that AIC1 could be competed out by oligonucleotides containing the binding site of the transcription factor NFY. In the present study, DNA binding gel electrophoresis and competition assays showed that NFY and AIC1 recognized the same binding site on element AIC. This site contains a CCACT motif and differs by one residue from the consensus CCAAT binding motif of NFY. Cotransfection of HepG2 cells with both the -177 to -148 apoA-I CAT constructs and plasmid expressing NFY alpha and NFY beta, transactivated the apoA-I promoter by 1.8 fold, indicating that NFY is a positive activator of the apoA-I gene.