Brd4 Is Displaced from HPV Replication Factories as They Expand and Amplify Viral DNA
Figure 4
In the presence of a replicating viral origin, the size of E1/E2 foci increases and Brd4 is displaced.
A. Human keratinocytes were cotransfected with expression vectors for HPV16 E1 and E2 in the presence of a plasmid containing the minimal HPV16 replication origin, p16ori (+ ori) or a control plasmid without the origin, pKS (− ori). The E1 and Brd4 proteins were detected by immunofluorescence. Representative foci from each condition are shown. The diameter of E1 foci was measured using Bitplane Imaris. Error bars represent the standard error of the mean. B. Human keratinocytes were cotransfected with expression vectors for HPV16 E1 and E2 in the presence of a plasmid containing the minimal HPV16 replication origin, p16ori (+ ori) or a control plasmid without the origin, pKS (− ori). E1 and E2 expression was induced four hours before fixation in the presence of 25 µg/ml AraC and E1, E2 and Brd4 proteins were detected by immunofluorescence. Representative cells from each condition are shown. The diameter of E1 foci was measured using Bitplane Imaris. Error bars represent the standard error of the mean.