Figure 3

Effects of RNA binding mutations on tethered MBNL1 repressor and activator function. A. The Tpm1 ΔBP DMS2 minigene was transfected alone (lane 1), or co-transfected with MS2 (lane 10), or MS2 fused to the N-terminal (aa 2–253) of MBNL1 (lanes 2–9). The MBNL-MS2 fusion proteins were WT (lane 9) or had the indicated ZF mutations (lanes 2–8). The horizontal dashed lines indicate the activity of the wild type N-MS2 (lane 9). Values significantly different from wild type N-MS2 in panels A and C: **, P < 0.01; *** P < 0.001; ns, not significant. Note that although the values for the M1234 mutant in lane 8 of panels A and C are statistically significant, the lack of protein expression of the M1234 mutant (panel B) means that meaningful conclusions cannot be drawn. B. Anti-MS2 western blot of MBNL-MS2 fusion proteins used in panels A and C. C. The Vldlr MS2 minigene was transfected alone (lane 1), or co-transfected with MS2 (lane 10), or MS2 fused to the N-terminal (aa 2–253) of MBNL1 (lanes 2–9). The MBNL-MS2 fusion proteins were WT (lane 9) or had the indicated ZF mutations (lanes 2–8). The horizontal dashed lines indicate the activity of the wild type N-MS2 (lane 9).