Expression of the active rnpB ribozyme inhibits IRES activity. (A) Time course of reporter translation in response to expression of the rnpB ribozyme. The luciferase activity (measured as relative light units, RLU) of extracts prepared from cells transfected with the indicated constructs (0.33 μg/105 cells) was determined over a period of 24 h and normalized to the concentration of protein in the extract. Values of luciferase activity/protein correspond to the average obtained from triplicate wells and performed in at least three independent assays. (B) Immunodetection of luciferase expression by Western blot. (C) Levels of inhibition of IRES-dependent translation by expression of the RNase P ribozyme. The luciferase activity determined at the indicated time in extracts of cells transfected with the ribozyme constructs was normalized to the value observed in the IRES construct set to 100%. Error bars correspond to the standard deviation.
