Figure 3. Activity to regulate Cyclin A is conserved in pUL21a of primate CMVs.

(A) MRC-5 cells expressing tetracycline-inducible pUL21a from HCMV (Hu-UL21a), ChCMV (Ch-UL21a), or RhCMV (Rh-UL21a) were analyzed as described in 2D. Note that the HCMV pUL21a antibody recognized the slightly larger ChCMV pUL21a but not RhCMV pUL21a, likely due to the lack of cross-reactivity with this more divergent protein. (B) Cells expressing pUL21a variants from (A) were infected with either ADgfp or ADsubUL21a at an MOI of 0.1 TCID₅₀/cell with or without tetracycline. Culture supernatant was collected 6 days post infection (dpi) and titer of cell free virus was determined by TCID₅₀ assay. Dashed line indicates the limit of detection.