FIG. 8.

Model summarizing a possible mechanism of Sp1/Sp3-dependent modulation of VZV DNA origin-dependent replication during the VZV life cycle. In this model, Sp1 and Sp3 cycle on and off the consensus GGGCGGG site within GC box 1 in response to requirements for their presence for IE62-mediated transcription at promoter sites within the VZV genome. Thus, their presence during the early phase of the virus life cycle would be minimal, resulting in increased DNA replication which also peaks at this phase. IE, immediate early.