Figure 1.

 Cotransfection of hepatitis B virus (HBV) and the cAMP response element binding protein (CREB) inductor protein kinase A (PKA) leads to increased HBV-S RNA and small hepatitis B surface protein (SHB) expression. (A) Northern Blot analysis. HBV wild-type (wt) plasmid and different concentrations of PKA plasmid were cotransfected. RNA was harvested 24 and 48 hours after transfection, and HBV RNA was detected with a radioactive labelled HBV specific probe. 28S and 18S RNA signals are shown to prove equal loading of RNA. Transfection with pBluescript (pBS) alone served as a negative control. One representative northern blot experiment is shown. pg/pc, pregenomic/precore RNA. (B) Quantification of HBV-S RNA normalised to 18S. Mean (SD) based on three independent experiments. Values are given relative to PKA 0 µg. Significant difference (*p<0.05) compared with PKA 0 µg. (C) Western blot analysis. HBV wild-type (wt) plasmid and different concentrations of PKA plasmid were cotransfected. Total cellular proteins were harvested 48 and 72 hours after transfection, and S-HBs (small HBs protein) was detected with an anti-HBs antibody. Anti-α-tubulin staining of the same blot was performed to prove equal loading. Transfection with pBS served as a negative control. Cotransfection with 1 µg of PKA resulted in increased HBs protein expression.