FIG. 7.

Increased Bcl-3 coimmunoprecipitates with NF-κB1 after transfection with NF-κB1 siRNA. (A) Coimmunoprecipitation of p105/p50 with p100/p52 and Bcl-3 was measured after knockdown with 100 pmol irrelevant siRNA, 100 pmol NF-κB1 siRNA, 100 pmol Bcl-3 siRNA, or 50 pmol NF-κB1 and Bcl-3 in C33A cells stably expressing pCDNA3 or 1-231. Stable cells were transfected with the siRNA indicated above the immunoblot. Lanes 1 and 2 are a direct load of protein lysates from pCDNA3 and 1-231 stable cells. Lanes 3 to 7 are immunoprecipitated with rabbit immunoglobulin G (IgG) isotype control, lanes 8 to 12 are immunoprecipitated with anti-p100/p52 (α-p100/p52), and lanes 13 to 17 are immunoprecipitated with anti-Bcl-3 (α-Bcl-3). All immunoprecipitates were immunoblotted with anti-p50. (B) Coimmunoprecipitation of Bcl-3 with anti-p105/p50 (α-p105/p50) and anti-p100/p52 was measured after knockdown with siRNAs as described for panel A with C33A cells stably expressing pCDNA3 or 1-231. Stable cells were transfected with the siRNA indicated above the immunoblot. Lanes 1 and 2 are direct loads of protein lysates from pCDNA3 and 1-231 stable cells. Lanes 3 to 7 are immunoprecipitated with goat IgG isotype control, lanes 8 to 12 are immunoprecipitated with anti-p105/p50, and lanes 13 to 17 are immunoprecipitated with anti-p100/p52. The complexes were immunoblotted with anti-Bcl-3. (C) Coimmunoprecipitation of anti-p100/p52 with anti-p105/p50 and Bcl-3 was measured after siRNA knockdown as described for panel A in pCDNA3 and 1-231 stable C33A cells. Stable cells were transfected with the siRNA indicated above the immunoblot. Lanes 1 and 2 are a direct load of protein lysates from pCDNA3 and 1-231 stable cells. Lanes 3 to 7 are immunoprecipitated with mouse IgG isotype control, lanes 8 to 12 are immunoprecipitated with anti-p105/p50, and lanes 13 to 17 are immunoprecipitated with anti-Bcl-3. The immunoprecipitates were immunoblotted with anti-p52.