Brd4 Is Displaced from HPV Replication Factories as They Expand and Amplify Viral DNA
Figure 5
HPV origin containing plasmids replicate to high levels in E1/E2 nuclear foci.
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, and following a brief fixation, origin containing DNA was detected by FISH. The images shown are optical slices from cells that were digitally reconstructed by deconvolution of high resolution 3D stacks of confocal images. E1 is shown in green, Brd4 in cyan, and origin DNA in red. The dashed blue lines represent the perimeter of the nuclei (identified by DAPI staining, not shown).