FIG. 5.
Coactivation of PPARα by PGC-1 requires intact AF2 and LXXLL motifs. To examine functional correlates of the GST pulldown interaction studies, a mammalian cell hybrid system was employed (shown schematically at the top). PPARα or PPARΔAF2 was fused to the Gal4 DNA binding domain (DBD) and cotransfected with an expression plasmid encoding PGC-1 or a mutant PGC-1 in which the LXXLL motif was mutated (PGCLXXFF). A plasmid containing the Gal4 upstream activating sequence (UAS) multimerized upstream of TK luciferase [(UAS)3TKLuc] was used as a reporter in these experiments. Transfections were performed in the presence of the PPARα ligands (oleic acid or ETYA) or vehicle controls. Bars represent mean RLU normalized (=1.0) to the value obtained with Gal4DBD cotransfected with expression plasmid backbone in the presence of vehicle.