Figure 7.

Changes in mRNA stability cause A-to-I editing dynamics. (A) Correlation of A-to-I editing and mRNA half-life in response to H₂O₂, zinc and glucose. S. pyogenes SF370 was exposed to 1.0 mM H₂O₂, 0.5 mM ZnSO₄ or 0.5% (w/v) glucose at mid-logarithmic phase for 30 min, and rifampicin was added to determine half-lives by qRT-PCR. Half-lives, editing levels and Spearman's ρ are shown. (B)S. pyogenes P_tet-rnjA, harbouring the AHT-inducible P_tet promoter to control the expression of the RNase J1-encoding rnjA, was grown in the presence or absence of 0.1 ng/ml AHT in THY to mid-logarithmic growth phase, and A-to-I editing was analysed by RNA sequencing. Absolute editing levels were transformed to editing z scores and are shown as a heatmap. (C)S. pyogenes P_tet-rnjA was grown in the presence or absence of 0.1 ng/ml AHT in C medium to mid-logarithmic growth phase and treated with rifampicin. Editing levels and mRNA half-lives were analysed as described in (A), and paired replicate values are shown by lines. (D) Rifampicin assay and editing analysis were performed as in (C), but with S. pyogenes P_tet-tadA grown in the presence or absence of 100 ng/ml AHT. (C, D) Statistical analysis was performed using paired t-tests, and P-values were adjusted for a false discovery rate of 5% using the procedure of Benjamini, Krieger and Yekutieli.