Figure 2. Analysis of small RNAs associated with purified proteasomes from different cell lines.

(A) Coomassie stains of 26S proteasomes purified from K562 cells non-treated or treated with doxorubicin. (B) Affinity-purified 26 proteasomes from K562 cells (left) and HEK293 (right) cells stably expressing PSMD14-6His-Tev-Biotin binding domain (HTB). Positions of 19S and 20S sub-complexes in the gel are shown. Markers of molecular weight (Fermentas Life Sciences) are indicated on the left (A) and on both sides in panel (B). (C) Electrophoregram of the RNA component associated with proteasomes purified from K562 cells. Low molecular weight markers are shown on the right (5S, 4.5S and 4S RNA species correspond to 120 nt, 100nt, and 80 nt, respectively). (D) ³²P-labeled lmw RNA species isolated from conventionally (K562 cells non-treated and treated with DR) and affinity purified proteasomes (HEK293 cells expressing PSMD14-HTB). Markers of molecular weight (Fermentas Life Sciences) are indicated on the right. RNA species were separated by electrophoresis in denaturing 8% PAAG with 8 M urea.