Human Cytomegalovirus Immediate Early Interaction with Host Nuclear Structures: Definition of an Immediate Transcript Environment

The development of an induced transcript environment was investigated at the supramolecular level through comparative localization of the human cytomegalovirus immediate early (IE) transcripts and specific nuclear domains shortly after infection. Compact aggregates of IE transcripts form only adjacent to nuclear domain 10 (ND10), and the viral protein IE86 accumulates exclusively juxtaposed to the subpopulation of ND10 with transcripts. The stream of transcripts is funneled from ND10 into the spliceosome assembly factor SC35 domain through the accumulation of IE86 protein, which recruits some components of the basal transcription machinery. Concomitantly the IE72 protein binds to ND10 and later disperses them. The domain containing the zinc finger region of IE72 is essential for this dispersal. Positional analysis of proteins IE86 and IE72, IE transcripts, ND10, the spliceosome assembly factor SC35, and basal transcription factors defines spatially and temporally an immediate transcript environment, the basic components of which exist in the cell before viral infection, providing the structural environment for the virus to usurp.