English: (A) HF cells were mock-infected or infected with HCMV at an MOI of 5. Total cell lysates were prepared at indicated time points and immunoblotting was performed with antibodies that recognize IE1 (6E1), IE2 (12E2), or both IE1 and IE2 (8131). The β-actin levels are shown as a loading control. The bands indicated as open circles appear to be non-specific or represent other modified forms of IE1 and IE2. (B) 293T cells in six-well plates were cotransfected with plasmids expressing IE1 (1 µg), flag-SUMO-1 (1 µg), and increasing amounts of IE2 (0.3, 1, and 3 µg), as indicated. At 48 h, total cell lysates were prepared and immunoblot assays were performed with anti-IE1/IE2 antibody.