(A) Immunoblot analysis of IRE1, XBP1, and TRAF2-deficient (Ern1, Xbp1, and Traf2 ko) cell lines. Two ko clones were generated for each gene by CRISPR/Cas9 gene editing using different gRNAs. Cells were treated for 4 hr with Thapsigargin (Tg) to induce Xbp1 mRNA splicing and to increase XBP1 expression. (B,C) Multistep MCMV replication kinetics in Ern1, Xbp1 and Traf2 ko cells, respectively. Cells were infected with MCMV-GFP (MOI 0.1). Virus titers in the supernatants were determined by titration and are shown as means ± SEM of 3 biological replicates. (D–F) Immunoblot analysis of viral protein expression kinetics in Ern1, Xbp1 and Traf2 ko cells, respectively. Cells were infected with MCMV-GFP (MOI 3) and harvested at different times post infection. Expression levels of the viral immediate-early 1 (IE1) protein, the major DNA binding protein (M57; an early protein), and glycoprotein B (gB; a late protein) were detected with specific antibodies, β-Actin served as loading control. Immunoblots are representative of 2 independent experiments. Data provided in Figure 3—source data 1. Additional data provided in Figure 3—figure supplement 1.