Adaptive Evolution of Mus Apobec3 Includes Retroviral Insertion and Positive Selection at Two Clusters of Residues Flanking the Substrate Groove
Figure 7
Antiviral activity of mA3 mutants carrying BALB/c residues at the 34–38 and 134–139 clusters.
293T cells were cotransfected with Friend virus clone pLRB302 and the indicated mA3 variants. The experiment was repeated six times with some experimental variations; shown are two representative experiments. One experiment (left panel) used 3 µg of pLRB302 and 1 µg of mA3. The second experiment (right panel) used 4 µg of pLRB302 and 0.5 µg of mA3, and total DNA amounts were adjusted to 6 µg with empty pcDNA3.1(−) vector DNA; mA3 was reduced because titration experiments showed 0.5 µg to have antiviral activity (not shown). Infectivity of collected Friend virus was assayed by the XC overlay test normalized against reverse transcriptase activity (experiment 1) or virus capsid protein in pelleted virus (experiment 2). Infectivity of virus produced in the absence of mA3 was defined as 100%, and infectivity of the other viruses is given as a percentage of the control. Virus infectivity was determined 6 times in both experiments.