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Received July 19, 2010
Peroxisome proliferator-activated receptor α (PPARα), one of the key ligand-activated nuclear receptors interacting with PPAR response elements (PPREs), may trigger the expression of PPAR-responsive genes and be involved in the transcriptional regulation of lipid metabolism, energy balance, and some diseases. Previous studies have demonstrated that the mouse Ppsig gene is a novel PPARα target gene taking a pivotal role in maintaining energy balance during fasting. Disparity between humans and rodents in their PPAR systems requires corroborating experiments to determine whether the hPpsig gene (Ppsig homologous gene in human) is also a PPARα target gene. In this work, eight putative PPREs in the promoter and first intron of hPpsig were identified. However, only one intronic PPRE could respond to PPARα by transient transfection. Furthermore, the binding activity of PPARα with this intronic PPRE was confirmed by electrophoretic mobility shift assay in vitro. This investigation might help to elucidate the transcriptional regulatory mechanisms of Ppsig in humans.
KEY WORDS: EMSA, human Ppsig, intronic PPREs, PPARα, transcriptional regulation