FIG. 6.
RIP140 represses transcription by binding to hCtBP1. Gal4-RIP140 fusion protein containing the CtBP interaction motif was analyzed for the ability to repress a Gal4-SV40-CAT reporter. The wild type (WT) and the K446Q and AIAL mutants were compared to Gal4-ZEB (700-776). COS7 and HepG2 cells were transiently transfected with 300 ng of reporter, 700 ng of Gal4 fusion constructs, and 20 ng of SV40-lacZ. CAT protein produced in the absence of repressor (−) is indicated. The total amount of DNA was kept constant using empty pcDNA3 vector. Protein levels of the RIP140 constructs are shown in the insets. CAT protein production was measured 48 h after transfection using an enzyme-linked immunosorbent assay system (Roche Molecular Biochemicals), and values are normalized to β-galactosidase activity.