The discrete pUL17 nuclear localisation is not an intrinsic property. When expressed in fusion with eGFP, pUL17 localizes mainly in the cytoplasm in transfected CESC (A) whereas eGFP alone is randomly distributed in the cell (B). A similar localization is observed for the GFP-UL17 in DF1 cells (C). The localization of UL17-HA, expressed from pCDNA3-UL17-HA, was also predominantly cytoplasmic however the recombinant protein did not form large aggregates in the cytoplasm (D). When expressed in COS-7 cells, the HA tagged (E left panel) or the GFP fusion protein (E right panel) showed similar fluorescence patterns. The HA tag was revealed by staining with anti-HA7 monoclonal antibody and an anti-mouse antibody conjugated to Alexa 488. The nuclei were counterstained with Hoechst 33342 dye.