Efficiency of nuclear entry. (A) Percentages of total viral genomes in the cell that entered the nucleus (nuc) by 24 h. Two mutants, D528A and mut22, accumulated significantly lower and higher percentages of genomes, respectively, in the nucleus than the wt, as determined by one-way ANOVA (F[7,17] = 17.37; P < 0.0001; n = 3). Tukey's post hoc comparisons to the wt are indicated (***, P < 0.001). There was no significant difference between the remaining mutants or the A20-bound virus and the wt. cyt, cytoplasm. (B) The number of viral genomes per nucleus (gen/nuc) is indicated for each mutant or the A20-bound wt virus (top row) at 24 h (means of data from three experiments) regardless of variations in cell entry or nuclear accumulation rates.