FIG 1.

EBV BBLF1 is a late lytic protein. (A) Identification of endogenous BBLF1. Akata cells were treated with anti-human IgG antibody, and HEK293-EBV and AGS-EBV cells were transfected with the BZLF1 expression vector for lytic reactivation. Cells were harvested at 48 h after reactivation and then subjected to immunoblotting (IB) using a newly generated anti-BBLF1 antibody. (B) B95-8 cells were treated with T/A/B (12-O-tetradecanoylphorbol-13-acetate [TPA], A23187, and sodium butyrate) for lytic induction, collected at the indicated time points and monitored for viral protein expression via IB for BZLF1 (IE), BMRF1 (E), BALF4 (L), and BBLF1, with GAPDH as a housekeeping gene. (C) B95-8 cells were treated with T/A/B with or without phosphonoacetic acid (PAA), which is a viral DNA polymerase inhibitor. (D) HEK293 cells stably carrying the EBV WT or BDLF4 knockout viral genomes were lytically reactivated through BZLF1 transfection in the presence or absence of pBDLF4, harvested after 48 h, and subjected to IB with the indicated antibodies.