Previous Article | Next Article ![]()
J. Virol., 10 1997, 7387-7392, Vol 71, No. 10
Z Xu, G Jensen and TS Yen
Hepatitis B virus (HBV) codes for three forms of surface protein. The
minor, large form is translated from transcripts specified by the preS1
promoter, while the middle and small forms are translated from transcripts
specified by the downstream S promoter. When the large surface protein is
overexpressed, the secretion of both subviral and virion particles is
blocked within the secretory pathway. We show here that overexpression of
the large surface protein leads to up to a 10- fold activation of the S
promoter but not of an unrelated promoter. Neither the middle nor the small
surface protein, nor a secretable form of the large surface protein,
activates the S promoter, but agents that induce endoplasmic reticulum (ER)
stress have an effect similar to that of the large surface protein. The
large surface protein also activates the S promoter in the context of the
entire viral genome. Therefore, it appears that HBV has evolved a feedback
mechanism, such that ER stress induced by accumulation of the large surface
protein increases the synthesis of the middle and small surface proteins,
which in combination with the large surface protein can form mixed,
secretable particles. In addition, like other agents that induce ER stress,
the large surface protein can activate the cellular grp78 and grp94
promoters, raising the possibility that it may alter the physiology of the
host cell.
Copyright © 1997, American Society for Microbiology
Activation of hepatitis B virus S promoter by the viral large surface protein via induction of stress in the endoplasmic reticulum
Department of Pathology, University of California, San Francisco, USA.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|