Research paperHuman cytomegalovirus microRNA miR-US25-1-5p inhibits viral replication by targeting multiple cellular genes during infection

•hcmv-miR-US25-1-5p is highly expressed in HCMV-infected MRC5 cells.•Over-expression of miR-US25-1-5p reduces HCMV DNA replication.•Thirty five putative targets of hcmv-miR-US25-1-5p were identified.•YWHAE, UBB, NPM1 and HSP90AA1 are direct targets of hcmv-miR-US25-1-5p.•hcmv-miR-US25-1-5p mediated repression of the targets inhibits HCMV DNA replication.

MicroRNAs (miRNAs) play important roles in regulating various cellular processes in plants, animals, and viruses. This mechanism is also utilized by human cytomegalovirus (HCMV) in the process of infection and pathogenesis. The HCMV-encoded miRNA, hcmv-miR-US25-1-5p, was highly expressed during lytic and latent infections, and was found to inhibit viral replication. Identification of functional target genes of this microRNA is important in that it will enable a better understanding of the function of hcmv-miR-US25-1-5p during HCMV infection. In the present study, 35 putative cellular transcript targets of hcmv-miR-US25-1-5p were identified. Down-regulation of the targets YWHAE, UBB, NPM1, and HSP90AA1 by hcmv-miR-US25-1-5p was validated by luciferase reporter assay and Western blot analysis. In addition, we showed that hcmv-miR-US25-1-5p could inhibit viral replication by interacting with these targets, the existence of which may impact virus replication directly or indirectly.