FIG 3.

Analysis of the phosphorylation state of the HBc CDM mutants by Phos-tag SDS-PAGE. HepG2 cells were transfected with HBV replicon constructs expressing the indicated CDM mutants or WT HBc. (C) The transfected cells were harvested at 5 days posttransfection, cell lysates were subjected to Phos-tag SDS-PAGE, and HBc proteins were detected by immunoblot analysis using the indicated anti-HBc MAbs. (A and B) HBc protein expressed and purified from E. coli control (A) or cytoplasmic lysate from pCI-HBc-3A-transfected HEK293T cells (B) was also used as a nonphosphorylated or hypophosphorylated HBc control, respectively. Hyper, hyperphosphorylated HBc; Hypo, hypophosphorylated HBc. *, nonspecific background bands. The numerals 1 to 5 denote the hypophosphorylated HBc-3A species, with species 1 comigrating with the unphosphorylated HBc.