Fig. 5.

Bcl-3 interacts with β-catenin and is required for β-catenin recruitment to Wnt target gene promoters. a HCT116 cell lysates were prepared, and anti-Bcl-3 antibody was used in IP followed by immunoblot using the indicated antibodies. b Co-IP analyses of Bcl-3-Flag and β-catenin truncated expression vectors (HA-tagged β-catenin (WT) or N-terminal 89 amino acid deletion mutant of β-catenin) in 293 T cells and cell lysates with anti-Flag antibodies. c Representation of the wild-type Bcl-3 protein and Bcl-3 mutants. d Co-IP analyses of β-catenin-HA and Bcl-3-truncated expression vectors (WT: 1–446 amino acids; dN30: 31–446 amino acids; dN125: 126–446 amino acids; dC116: 1–330 amino acids, and dNC: 126–330 amino acids) in HEK293T cells, and cell lysates were immunoprecipitated with anti-Flag antibodies. e 293T cells were cotransfected with the indicated plasmids and TOP/Flash or FOP/Flash reporter plasmid, treated with Wnt3a for 24 h, and total cell lysates were collected to measure the firefly and Renilla luciferase activities. Values are means ± SD for each cohort (n = 3). ***p < 0.001 by two-tailed Student’s t-test. f, g ChIP assays on the promoter regions of the CD133 and AXIN2 genes were performed in control and Bcl-3-silenced HCT116 cells. h Co-IP analyses of the β-catenin and TCF-4 interaction in control and Bcl-3-silenced HCT116 cells