FIG. 5.

L11 inhibits HDM2-mediated p53 ubiquitination and degradation. (A) U2OS cells were transfected with (+) or without (−) the indicated plasmids. At 36 h after transfection, cells were treated with proteasome inhibitor MG132 (50 μM) for 4 h prior to cell lysis. Clarified cell lysate was immunoprecipitated (IP) with anti-p53 antibody, and washed immunoprecipitates were resolved by SDS-PAGE followed by immunoblotting with anti-HA antibody. Expression of individual transfected proteins was determined by direct immunoblotting (bottom panels). WB, Western blotting. (B) Total lysates prepared from cells transfected with (+) or without (−) the indicated plasmids were electrophoretically separated before immunoblotting with the indicated antibodies was performed.