Fig. 3.

APOBEC1-mediated editing modulates protein production by altering 3′UTR regulation. (A) Effect of editing in protein production, in the absence of the editing enzyme. The 3′UTRs of interest depicted at the top of each plot were cloned directly from cDNA derived from wildtype BMDMs. A schematic at the top of each graph depicts the range of edited 3′UTRs tested. All error bars represent the SEM; statistical significance was obtained using a t test. LUC, luciferase. (B) Putative miRNA targets in APOBEC1-edited regions that overlap with Ago footprints. “Edited” (with C-to-T mutations reflecting APOBEC1-dependent changes) and “Unedited” (reflecting the genomic reference) footprint sequences were scanned for miRNA target regions (match to position 2–7, 1–6, or 3–8 of mature miRNA sequence). The miRNA targets that would be created (green) or disrupted (red) by an APOBEC1-editing event are depicted. (C and D) APOBEC1-editing disruption of putative miRNA target regions in the Sptssa and Rac1 3′UTRs. UN, unedited construct with a sequence consistent with the reference genome. ED, edited construct, mutated to reflect the editing event in question. A schematic depicting miRNA-site deletion or creation by APOBEC1 editing is shown at the top of each graph. The miRNA repression was calculated using the ratio of relative luciferase values (Materials and Methods) between miRNA and unrelated miRNA for each edited and unedited pair. The star indicates values below 0 or no relative repression (n = 5).