FIG. 7.

The E2FBP1 ARID is required for repression of accumulation of ICP0 transcripts. (A) E2FBP1 decreases accumulation of transcripts encoding ICP0 from HSV-1. TIG-3 cells at 43 PD were transformed with either a plasmid expressing E2FBP1 or empty vector, incubated for 44 h, and then infected with HSV-1 at an MOI of 1 for 30 min. Total cellular RNA was collected at the indicated times postinfection and subjected to RT-qPCR analyses. The upper chart represents the relative accumulation of ICP0 RNA, and the lower chart shows the relative accumulation of E2FBP1 RNA. Nontransformed TIG-3 cells (mock) served as a control for transformation. (B) E2FBP1 requires its ARID to repress accumulation of ICP0 RNA. TIG-3 cells at 45 PD were transformed with empty vector or plasmid expressing either wild-type (WT) or ΔA E2FBP1, incubated for 44 h, and then infected with HSV-1 at an MOI of 0.5 for 30 min. Total cellular RNA was then collected at the indicated times postinfection and subjected to RT-qPCR analyses. (C) Potential ARID3-binding motifs in the IE-0 promoter. The IRL region of HSV-1 strain F (GenBank accession no. GU734771) was searched for ARID3-binding consensus motifs. The DNA sequence constituting the promoter for IE-0 is shown, and boxes identify ARID3 consensus and consensus-like motifs. (D) Schematic representation of ARID3 consensus motifs residing in the IE-0 promoter and its truncated sequences linked upstream of the hRluc gene in reporter constructs. (E) Relative expression levels of hRluc activity in the presence or absence of wild-type or ΔA mutant E2FBP1 expressed from reporter constructs.