Figure 12.

Serine 13 is not required for productive HCMV replication in fibroblasts.A, serum-starved hTERT-BJ1 fibroblasts were infected with the indicated recombinant viruses at an MOI of 1. Cell-free virus was collected at 6 days post-infection (dpi) and titers were determined by plaque assay. Error bars denote SDs from three biological replicates. Statistical analysis utilized a two-tailed unpaired Student’s t test. n.s., not significant (p > 0.05). B, analysis as in panel (A) with infections at an MOI of 0.1 and harvest at 10 dpi. C, serum-starved hTERT-BJ1 fibroblasts were mock infected (M) or infected with the indicated recombinant viruses at an MOI of 0.1. Lysates prepared at the indicated dpi were analyzed by Western blotting with the indicated antibodies. A representative image from one of three independent biological replicates is shown. D, the protein levels of HA-tagged UL97 at 9 dpi from the experiment shown in panel (C) were quantified and normalized to GAPDH levels. The value of HA-tagged UL97-S13A (white bars) is presented relative to the value of HA-tagged WT UL97 (gray bars: set at 1). Error bars denote SDs. Statistical analysis utilized a two-tailed unpaired Student’s t test. ∗p < 0.05. E, cell-free virus was collected at 9 dpi of the experiment shown in panel (C) and titers were determined by plaque assay. Error bars denote SDs. Statistical analysis utilized a two-tailed unpaired Student’s t test. n.s., not significant (p > 0.05). HCMV, human cytomegalovirus; MOI, multiplicity of infection.