MRN activities participating in AAV replication. (A) HeLa shRad50 cells were transfected with a combination of three plasmids (25 nmol each) expressing Rad50, Mre11, and Nbs1 or with an equivalent amount of a control plasmid (GFP). Where indicated, plasmids encoding a mutated Rad50 protein (mRad50 for S1202R) or Mre11 (mMre11 for Mre11-3) protein were used. Forty-eight hours posttransfection, cells were coinfected with wt AAV and HSVΔPol as indicated previously. MRN proteins (A) and AAV DNA (B) were analyzed 24 h later. qPCR results are expressed as the relative increase in AAV replication over that in mock-transfected HeLa shRad50 cells. *, P < 0.05. (C) HeLa cells were pretreated with Mirin (50 μM) or DMSO (mock) for 4 h and then infected with wt AAV and HSVΔPol. AAV DNA levels were measured by qPCR as indicated above and expressed relative to those in DMSO-treated cells.