Figure 2.

Diagram of the timeline of events following nuclear delivery of viral genomes. (1) HPV genomes are delivered into the nucleus inside the transport vesicle with a majority of L2 protein's C-terminus on the nuclear side. This event occurs during mitosis. After reformation of the nuclear membrane, L2 protein likely interacts with PML protein through SUMO interactions and recruits PML protein. (2) As the G1 phase continuous to progress, PML protein assembles around HPV-harboring vesicles. (3) Sometime during the engulfment of virus-harboring vesicles by PML protein, the membranous vesicle is lost by an unknown mechanism. We hypothesize that this step allows for the initiation of transcription. (4) Even later in interphase, Sp100 is recruited to the viral genome. The current working hypothesis is that Sp100 recruitment results in repression of viral transcription.