Fig 4.

Rta enhances the capacity of Z(S173A), a replication-defective ZEBRA regulatory domain mutant, to activate viral replication and late gene expression. (A) Total DNA prepared from BZKO cells transfected with wt ZEBRA, Z(S173F), and Z(S173A) in the absence and presence of Rta or a mixture of all the EBV replication proteins was analyzed by quantitative PCR for the level of the upstream oriLyt region as a marker for viral replication. The relative DNA concentration was calculated using the standard curve method. (B) Immunoblots of cell lysates prepared from the same cell lysates were probed with antibodies against FLAG, Rta, Z, and FR3. RPs, 2 μg of each of the six EBV replication proteins (BBLF4, BBLF2/3, BSLF1, BALF2, BMRF1, and BALF5).