FIG 1.

Schematic overview of G₁/S cell cycle subversion strategies used by CMVs. Cell cycle effectors of HCMV (highlighted in blue) and MCMV (highlighted in red) target key factors in the regulatory network governing G₁/S transition. This results in a dissociation of downstream cell cycle activities, where viral stimulation of S-phase gene expression and nucleotide metabolism is accompanied by viral inhibition of cellular DNA synthesis. Phosphorylations are indicated by an encircled “P”; the inhibition or destabilization of host factors is represented by red lines with bar heads.