FIG. 4.

Topoisomerase IIα is activated by PKCδ in cells. (A) MOLT-4 cells were incubated in the presence (+) or absence (−) of rottlerin. Decatenation assays using nuclear lysates (Nuc. Lysates) were performed, and the reaction products were resolved on a 1% agarose gel. Cat. KDNA, catenated KDNA; Decat. KDNA, decatenated KDNA. (B) 293T cells were transfected with Flag vector, Flag-PKCδCF, or Flag-PKCδCF(K-R). Nuclear lysates were analyzed by decatenation assays (top blot). Cell lysates were subjected to immunoblot (IB) analysis with anti-Flag or antitubulin. (C and D) Nuclear lysates from pkcδ^+/+ and pkcδ^−/− MEFs were analyzed by the decatenation (C) and DNA relaxation (D) assays. (E) pkcδ^−/− MEFs were left untreated or treated with rottlerin for 1 h. Nuclear lysates were analyzed by the decatenation assays. DMSO, dimethyl sulfoxide.