The HSV-1 Exonuclease, UL12, Stimulates Recombination by a Single Strand Annealing Mechanism
Figure 4
UL12 but not ICP8 is necessary to increase single strand annealing during HSV infection.
(A) HR and (B) SSA reporter cell lines were transfected with an I-SceI expression vector and mock infected or infected with wild type HSV, or mutant viruses lacking UL12 or ICP8. The average frequency of repair for each condition was normalized as described in Figure 3. Error bars represent the standard error of the mean. The asterisk indicates statistically significant differences from samples transfected with I-SceI and mock infected (P≤0.01). (C) Representative western blot analyses of cell lysates from mock infected or HSV, ΔUL12 or ΔICP8 infected cells. Infected cell lysates expressed the viral ICP4 protein and actin serves as a loading control. (D) Representative western blot analysis of cell lysates from mock, HSV, ΔUL12, ΔICP8, ΔUL52 or ΔUL32 infected HEK293 cells. Cells were infected at a MOI of 2 PFU/cell and analyzed for expression 6 hours post infection.