Duck hepatitis B virus expresses a regulatory HBx-like protein from a hidden open reading frame

Chang, Shau-Feng, Netter, Hans Jurgen, Hildt, Eberhard, Schuster, Ralph, Schaefer, Stephan, Hsu, Yin-Chen, Rang, Andreas and Will, Hans (2001) Duck hepatitis B virus expresses a regulatory HBx-like protein from a hidden open reading frame. Journal of Virology, 75 1: 161-170. doi:10.1128/JVI.75.1.161-170.2001

Author Chang, Shau-Feng
Netter, Hans Jurgen
Hildt, Eberhard
Schuster, Ralph
Schaefer, Stephan
Hsu, Yin-Chen
Rang, Andreas
Will, Hans
Title Duck hepatitis B virus expresses a regulatory HBx-like protein from a hidden open reading frame
Journal name Journal of Virology   Check publisher's open access policy
ISSN 0022-538X
Publication date 2001-01
Year available 2001
Sub-type Article (original research)
DOI 10.1128/JVI.75.1.161-170.2001
Open Access Status DOI
Volume 75
Issue 1
Start page 161
End page 170
Total pages 10
Place of publication Washington, DC, United States
Publisher American Society for Microbiology
Collection year 2001
Language eng
Subject C1
270303 Virology
730101 Infectious diseases
Abstract Duck hepatitis B viruses (DHBV), unlike mammalian hepadnaviruses, are thought to lack X genes, which encode transcription-regulatory proteins believed to contribute to the development of hepatocellular carcinoma. A lack of association of chronic DHBV infection with hepatocellular carcinoma development supports this belief. Here, we demonstrate that DHBV genomes have a hidden open reading frame from which a transcription-regulatory protein, designated DHBx, is expressed both in vitro and in vivo. We show that DHBx enhances neither viral protein expression, intracellular DNA synthesis, nor virion production when assayed in the full-length genome context in LMH cells. However, similar to mammalian hepadnavirus X proteins, DHBx activates cellular and viral promoters via the Raf-mitogen-activated protein kinase signaling pathway and localizes primarily in the cytoplasm. The functional similarities as,well as the weak sequence homologies of DHBx and the X proteins of mammalian hepadnaviruses strongly suggest a common ancestry of ortho- and avihepadnavirus X genes. In addition, our data disclose similar intracellular localization and transcription regulatory functions of the corresponding proteins, raise new questions as to their presumed role in hepatocarcinogenesis, and imply unique opportunities for deciphering of their still-enigmatic in vivo functions.
Keyword Virology
Viral Replication
Transgenic Mice
Hepatocellular Carcinomas
Transactivation Function
Proteasome Complex
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Chemistry and Molecular Biosciences
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Created: Tue, 14 Aug 2007, 16:37:09 EST