FIG 1.

EBV BDLF4 protein is phosphorylated in a viral kinase-independent manner. (A) HEK293/EBV(WT) cells were transfected with FLAG-BDLF4 and BZLF1 expression plasmids (left). HEK293 cells were transfected with a FLAG-BDLF4-expressing plasmid (right). Lysates were either left untreated (–) or treated (+) with λ-protein phosphatase (λ-PPase), separated by conventional or phosphate affinity (Phos-tag) gel electrophoresis, and analyzed by immunoblotting using anti-FLAG and anti-GAPDH antibodies. (B) Lysates from HEK293/EBV(dBGLF4) cells coexpressing BZLF1 protein with WT BGLF4 or a kinase-dead (KD) mutant were analyzed as described for panel A.