Unconserved C terminal of human cytomegalovirus tegument protein pUL76 elicits nuclear aggresome formation and induces DNA damage in transfected cells

Background: the hcmv ul76 gene is a member of ul24 family in herpes virus and encodes a highly conserved herpes virus protein. inherited from common ancestor,members of herpes-ul24 family encode proteins with a conserved n terminal and varied in c terminal region. to define which region (conserved n terminal or unconserved c terminal) of ul76 was responsible for its ability to induce dna damage and aggresome formation,the wild-type ul76 gene and two deletion mutants were transfected to cells and analyzed by immunofluorescent staining,western blotting and comet assay. results: we report that the egfp-fusion proteins present as globular aggresomes and colocalize with γ-h2ax in cells transfected with either pegfp-ul76 or pegfp-ul76c. the relative expression level of γ-h2ax and percentage of cells with comet tails were elevated in pegfp-ul76 or pegfp-ul76c transfection groups compared to the control. conclusion: our findings suggest that the unconserved c terminal (not the conserved n terminal) of pul76 was sufficient to induce dna damage and aggresome formation in transfected cells. © 2015 zhang et al.