The activity of human APOBEC3G on the ssDNA mutagenesis reporter system.

<p>For all graphs: each data point represents the value from an independent experimental replicate; each bar represents the median value across all independent replicates of a given genotype and treatment combination; * denotes P<0.05; ** denotes P<0.01; *** denotes P<0.001; and ns denotes P>0.05. (A) Expression of human APOBEC3G from a tetracycline-regulatable plasmid was well-tolerated in reporter strains. Median viability was >70%. (B) APOBEC3G induced an increased frequency of <i>CAN1</i> loss of function, specifically in ssDNA. Mutagenicity was enhanced over three-fold in cells deleted for <i>UNG1</i>, which encodes uracil-DNA N-glycosylase. Notice the lack of mutagenesis in mid-chromosome reporter controls, where the DNA remained double-stranded. (C) Similarly, APOBEC3G induced an increased frequency of simultaneous <i>CAN1</i> and <i>ADE2</i> double loss of function, in an ssDNA-dependent manner. Deletion of <i>UNG1</i> enhanced mutagenicity by almost six-fold.