This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kim, J.-H.
Right arrow Articles by Ahn, B.-Y.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kim, J.-H.
Right arrow Articles by Ahn, B.-Y.

 Previous Article  |  Next Article 

Journal of Virology, July 2003, p. 7166-7173, Vol. 77, No. 13
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.13.7166-7173.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.

Hepatitis B Virus Core Protein Stimulates the Proteasome-Mediated Degradation of Viral X Protein

Jung-Hwan Kim, Seongman Kang, Joon Kim, and Byung-Yoon Ahn*

School of Life Sciences & Biotechnology, Korea University, Seoul 136-701, Korea

Received 6 January 2003/ Accepted 10 April 2003

Hepatitis B virus (HBV) X protein (HBx) plays an essential role in viral replication and in the development of hepatocellular carcinoma. HBx has the ability to transactivate the expression of all HBV proteins, including the viral core protein HBc. Consistent with its regulatory role, HBx is relatively unstable and is present at low levels in the cell. We report here that the level of HBx was significantly reduced by the coexpression of HBc in cultured human hepatoma cells, whereas the level of HBx mRNA was unaffected. The repression of HBx by HBc was relieved by treating cells with the proteasome inhibitor MG132, indicating that HBc acts by stimulating the proteasome-mediated degradation of HBx. Moreover, the inhibitory effect of HBc was specific to HBx and did not affect other proteins, including p53, a known target of the proteasome. Although no direct physical interaction between HBc and HBx could be demonstrated, mutational analysis indicated that the C-terminal half of HBc is responsible for its inhibitory effect. These results suggest that HBc functions as a novel regulator of the HBV life cycle and of hepatocellular carcinogenesis through control of the HBx level via an inhibitory feedback type of mechanism.

* Corresponding author. Mailing address: School of Life Sciences & Biotechnology, Korea University, Anamdong 5-1, Sungbuk, Seoul 136-701, Korea. Phone: 82 2 3290 3432. Fax: 82 2 927 9028. E-mail: ahnbyung{at}korea.ac.kr.

Journal of Virology, July 2003, p. 7166-7173, Vol. 77, No. 13
0022-538X/03/$08.00+0     DOI: 10.1128/JVI.77.13.7166-7173.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Yuksek, K., Chen, W.-l., Chien, D., Ou, J.-h. J. (2009). Ubiquitin-Independent Degradation of Hepatitis C Virus F Protein. J. Virol. 83: 612-621 [Abstract] [Full Text]  
  • Sohn, S.-Y., Kim, S.-B., Kim, J., Ahn, B.-Y. (2006). Negative regulation of hepatitis B virus replication by cellular Hsp40/DnaJ proteins through destabilization of viral core and X proteins. J. Gen. Virol. 87: 1883-1891 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»