DRB reduces phosphorylation of ICP27 by CK2. (A) Uninfected or infected cells were labeled with either [35S]methionine (lanes 1 to 3) or [32P]orthophosphate (lanes 4 to 9) for 6 h in the presence or absence of DRB. Total extracts from uninfected cells (lane 1), cells infected with the ICP27 null mutant 27LacZ (lane 2), or wt-infected cells (lanes 3 to 9), in the absence (lanes 1 to 5) or presence of 5 μM (lanes 6 and 7) or 10 μM (lanes 8 and 9) of DRB, were used for immunoprecipitation of ICP27. A mixture of the monoclonal antibodies 1113 and 1119 against ICP27 was used, followed by SDS-polyacrylamide gel electrophoresis and autoradiography. A band migrating at 63 kDa, corresponding to full-length ICP27, is shown. (B) Western blot analysis was performed subsequently on the same membrane, using the ICP27 antibody H1113.