Figure 4.

The RGG + CTD Δ54 is required for translational repression.A, Coomassie stain of recombinant proteins with serial truncations to the CTD. The number of amino acids truncated from the CTD is indicated. B, in vitro translation of nLuc mRNA with 1 μM CTD truncated recombinant RGG + CTD proteins and protein storage buffer as a negative control. Data are shown as mean ± SD. n = 3 biological replicates. All recombinant protein tested was statistically significant compared to buffer negative control using a two-tailed unpaired t test with Welch’s correction (each comparison had p < 0.01). C and D, in vitro translation of nLuc mRNA with a titration of recombinant NT-hFMRP Δ54 (C) and NT-hFMRP Δ55 (D). n = 3 biological replicates. A nonlinear regression was used to calculate the IC₅₀ value for each truncation and is shown as the line with the 95% confidence interval (CI) included as a watermark. The IC₅₀ is reported ± 95% CI. CTD, C-terminal domain.