Figure 2. Quiescent mature miR-34 is not loaded into Ago2.

(a) A549 cells expressing Flag/HA-tagged EGFP or Ago2 were exposed to 4 Gy and lysed at the indicated time. miRNA expression was analysed from Flag-immunoprecipitates (top) and total lysate (bottom) by RT–qPCR. Results were normalized to miR-17. Graphed is the fold change±s.d., relative to non-irradiated cells; n=4 independent experiments. (b) 50 μg of total RNA extracted from A549 cells exposed to 4 Gy was untreated or treated with CIP and separated by denaturing PAGE. RNA was detected by northern blot with ³²P-labelled probes. U6 was used for normalization. Synthetic 5′OH and 5′P miR-34 from Dharmacon were used as size markers.