Fig. 10. CAP350 antagonizes transcriptional transactivation by endogenous PPAR in vivo. (A) H4IIEC3 cells were transfected with the reporter plasmid pTK-PPRE(x3)-Luc in the presence or absence of the PPAR ligand Wy-14,643 (100 µM) and increasing amounts of the CAP350 expression vector pMT-hCAP350 (0-0.5 µg/plate), as indicated. Luciferase activity was measured 48 hours posttransfection. The values are the average (±s.d.) fold-induction relative to untreated cells (taken as 1) from three independent transfections carried out in triplicate and normalized for protein and the levels of expression of ß-galactosidase from the plasmid pCMVLacZ used to control for transfection efficiency.(B) An amino-terminal fragment of CAP350 antagonizes PPAR-mediated transcriptional activity in an LXXLL-dependent manner. H4IIEC3 cells were transfected with the reporter plasmid pTK-PPRE(x3)-Luc in the presence or absence of the PPAR ligand, Wy-14,643 (100 µM) and expression vectors for EYFP-CAP350, EYFP-CAP350_1-890, EYFP-CAP350_1-890(LSHAA) or EYFP alone (designated by the (–) symbol), as indicated. Luciferase activity was measured as above.