Figure 2. Endogenous Tra2α functionally compensates for loss of Tra2β.

(a) UCSC genome browser screenshot35 showing significant clusters of iCLIP tags mapping directly to alternatively spliced exons within the CEP95, GLYR1 and ATRX genes (position of target alternative exons highlighted in grey). (b) Splicing inclusion of novel Tra2β target exons within ATRX, GLYR1 and CEP95 were only slightly affected by depletion of either endogenous Tra2α or Tra2β proteins, but were strongly affected by joint depletion of both Tra2α and Tra2β (red). PSI levels were measured by RT–PCR and capillary gel electrophoresis (lower panels) in three biological replicates (upper panels). (c) Splicing inclusion of 14 novel Tra2β target exons showed minimal splicing response to single depletion of either Tra2α or Tra2β, but showed highly significant splicing changes after joint depletion of both Tra2 proteins (complete data for all 14 exons is provided in Supplementary Fig. 4). Probability (P) values were calculated using an independent two-sample t-test between PSI levels of negative control siRNA-treated cells and TRA2A/TRA2B siRNA-treated cells (statistical significance: *P<0.05, **P<0.01, ***P<0.0001). All data represented by bar charts was generated from three biological replicates where error bars represent the s.e.m.