FIG 1.

DDB2 is required for efficient HCMV replication. (A to D) Replication of HCMV in normal and XPE (ddb2) cells. Normal (BJ) and XPE telomerase-life-extended dermal fibroblasts were infected at an MOI of 0.1. (A) Cell supernatants were assayed for infectious virus production by plaque assay. (B) Viral protein expression is altered in XPE cells. Immunoblot analyses for viral IE (IE1/IE2), E (pp65), and E/L (gB55) protein expression in BJ and XPE (lanes E) dermal fibroblasts are shown. (C and D) DDB2 depletion by siRNA compromises HCMV replication. HEL fibroblasts were transfected with siRNAs specific for DDB2 (siDDB2) or with a control siRNA (siCON) 24 h prior to infection with HCMV at an MOI of 0.1. (C) Cell supernatants were assayed for infectious virus production by plaque assay. (D) Transient depletion of DDB2 alters viral expression. The levels of DDB2 and viral IE (IE1/IE2), E (pp65), and E/L (gB55) protein expression were assessed by immunoblot analysis. (E and F) Effect of rescuing ddb2 on HCMV replication. XPE cells were infected with a retrovirus containing a DDB2 cDNA, and BJ and XPE cells were infected with a retrovirus containing an empty vector. Stably transduced cells were infected with HCMV at an MOI of 0.1. (E) Cell supernatants were assayed for infectious virus production by plaque assay. (F) Protein levels of DDB2 and actin were measured by immunoblot analysis. (A, C, and E) Mean values are shown, with bars denoting 1 standard deviation, for three independent experiments. For certain data points, error bars may be too tight to be visible.