FIG 7.

RNA editing substrates, intermediates, and products are held by the RESC. (A) Distribution of preedited, partially edited, and fully edited mRNAs among RESC modules and core editing complexes. Following rapid affinity pulldown, RNA was extracted from magnetic beads, separated on a 5% polyacrylamide–8 M urea gel, and probed for the respective mRNA species. [dT], total (Tot.) RNA was treated with RNase H in the presence of 18-mer (d[T]) to remove poly(A) tails; beads, IgG-coated magnetic beads were incubated with extract from the parental cell line. (B) Distribution of guide RNAs among complexes. The same RNA samples as described for panel A were probed for a specific gRNA. RNA amounts were normalized to tandem affinity purification (TAP)-tagged bait proteins detected by quantitative Western blotting with antibodies against calmodulin binding peptide. (C) The profile of the distribution of U-tail lengths in complex-bound transcripts. Bars above and below zero indicate relative enrichment and absence, respectively, of small RNAs with corresponding U-tails. A similarly sized fraction of total mitochondrial RNA was used as the reference.