Figure 3.

Electromobility shift assay using recombinant TDP-43, ETR-3 and CUG-BP1. Using a primer containing the T7 promoter sequence, an in vitro transcription assay was performed, allowing the synthesis of a 100 nt radiolabelled RNA containing the CFTR intron 8 polymorphic sequences (UG11, UG12 or UG13 followed by the U5 tract). Recombinant His-TDP-43, His-CUG-BP1 and His-ETR-3 were incubated for 20 min at 30°C with ³²P-labelled RNA (1pmole). Native polyacrylamide gels (6%) were used for separation. Ctrl represents the His-tag alone. The results are representative of five experiments with similar results. More TDP-43 protein (200 ng) than ETR-3 or CUG-BP1 (50 ng) was used to compensate for its lower RNA-binding activity. The arrow points to the protein-RNA complexes. The asterisk symbol points to the free RNA probe.