H. Lee et al., X-GENE PRODUCT ANTAGONIZES THE P53-MEDIATED INHIBITION OF HEPATITIS-BVIRUS-REPLICATION THROUGH REGULATION OF THE PREGENOMIC CORE PROMOTER/, The Journal of biological chemistry, 270(52), 1995, pp. 31405-31412
Employing the glutathione S-transferase column retention method and fa
r Western analysis, we found a physical association between tumor supp
ressor p53 and the hepatitis B virus X-gene product, which led us to s
tudy the function of observed interaction in relation to viral propaga
tion, In the cell culture-based in vitro replication system, expressio
n of p53 resulted in dramatic inhibition of viral replication, and thi
s inhibition was relieved by the coexpression of the X gene product in
a dose-dependent manner, Furthermore, the activity of pregenomic/core
promoter, responsible for the synthesis of pregenomic RNA, was almost
completely inhibited upon expression of p53, and as in the replicatio
n assay, the inhibition was rescued by the coexpression of the X-gene
product in a dose-dependent manner, Based on these results, we propose
that the ratio of X-gene product to p53 is an important factor determ
ining the fate of viral replication through modulation of the pregenom
ic/core promoter.