Immunoprecipitation of PARP in nuclei from adriamycin-treated U937 cells and proteasomal activity of PARP coimmunoprecipitates.
U937 cells were treated with 10−7 M adriamycin in the absence or presence of 1 mM 3-ABA for the time points indicated. Thereafter, the nuclei were isolated, lysed, and immunoprecipitated with a polyclonal rabbit anti-PARP antibody. (A) Immunoprecipitated proteins were separated by SDS-PAGE, transblotted, and visualized with a polyclonal anti-PARP and a polyclonal antiproteasome antibody, respectively. One experiment of 3 similar ones is presented. (B) Proteasome enzyme activity in the anti-PARP immunoprecipitated lysates was measured as suc-LLVY-MCA degrading activity. Data are given as mean ± SD from 3 parallel proteolysis assays corresponding to the Western blot in panel A.
