Triptolide (TPL) Inhibits Global Transcription by Inducing Proteasome-Dependent Degradation of RNA Polymerase II (Pol II)
Figure 3
TPL induced phosphorylation and proteasome-dependent degradation of Rpb1.
(A) Hela cells were pretreated with CHX (10 µM) for 0.5 h before addition of TPL (125 nM) and treated for another 3 h. Whole cell lysates were processed for Western blot analysis using antibodies as indicated. (B) Hela cells were pretreated with MG132 (20 µM) for 1 h and then treated with TPL at indicated concentrations for another 3 h. Whole cell lysates were subjected to SDS-PAGE and Western blot analysis. (C) Hela cells were treated with 125 nM TPL for various lengths of time (0–180 min) in the presence of MG132 (20 µM). Whole cell lysates were subjected to SDS-PAGE and Western blot analysis. β-Actin served as a loading control.