Fig. 3

Deletion mutants of SGIV ICP46 promoters. a Luciferase reporter assays of consecutive deletion mutants from − 3247 to + 44. b Luciferase reporter assays of consecutive deletion mutants from − 649 to + 42. c Luciferase reporter assays of P-196 (− 196 to + 42) and P-∆196 (with − 22 to + 42 deleted from P-196). DNA fragments decreasing in length and located upstream of the open reading frames for SGIV ICP46 was fused to a luciferase reporter gene. GS cells were transfected with these promoter constructs followed by SGIV infection at MOI of 2 at 24 h after transfection. Cells were harvested 6 h p.i. for luciferase reporter assays. Firefly luciferase activities were normalized based on the activity of Renilla luciferase. The mean Fluc/Rluc intensity of negative control was considered as 1. The plasmid numbers on the left side specify the beginning and end positions (TSS as + 1) of deletion mutants. TSS are marked by arrows. Error bars show SD of three independent experiments