Fig. 4.
Detection of PARP-dependent proteasome activations in different U937 leukemic cell variants.
U937, Diff-U937, Retro-U937, and TUR cells were treated with 10−7 M adriamycin for 15 minutes (maximal protesome activation) in the absence and presence of 1 mM of the PARP inhibitor 3-ABA, respectively, and subsequent anti-PARP immunoprecipitation was performed. (A) SDS-PAGE and immunoblot with a polyclonal rabbit anti-PARP antibody and a polyclonal rabbit antiproteasome antibody. (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.
