1887

Abstract

During chronic hepatitis B virus (HBV) infection, double substitution mutations in the basal core promoter (BCP) region frequently emerge that include A1762T/G1764A and the neighbouring C1766T/T1768A mutations, here termed BCP1 and BCP2, respectively. Due to a compact viral genome organization, BCP1 and BCP2 mutations result in amino acids changes in the overlapping X gene: K130M/V131I and F132Y, respectively. It has been shown that both BCP mutations lead to a modest increase in viral genome replication. However, the question of whether the alteration that occurs in the overlapping X gene might contribute to the increased viral genome replication has not been properly addressed. This study genetically separated the core promoter from the overlapping X gene using 1.3mer overlength HBV constructs and examined the impact of the X gene mutations on viral genome replication in HepG2 cells. Each BCP mutation resulted in modestly enhanced viral genome replication that occurred via augmented viral transcription. Therefore, it was concluded that these BCP mutations do not affect expression of the overlapping X gene or impair its stimulatory effect on viral genome replication.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/vir.0.010421-0
2009-09-01
2024-03-29
Loading full text...

Full text loading...

/deliver/fulltext/jgv/90/9/2272.html?itemId=/content/journal/jgv/10.1099/vir.0.010421-0&mimeType=html&fmt=ahah

References

  1. Baptista, M., Kramvis, A. & Kew, M. C.(1999). High prevalence of 1762T 1764A mutations in the basic core promoter of hepatitis B virus isolated from black Africans with hepatocellular carcinoma compared with asymptomatic carriers. Hepatology 29, 946–953.[CrossRef] [Google Scholar]
  2. Baumert, T. F., Rogers, S. A., Hasegawa, K. & Liang, T. J.(1996). Two core promotor mutations identified in a hepatitis B virus strain associated with fulminant hepatitis result in enhanced viral replication. J Clin Invest 98, 2268–2276.[CrossRef] [Google Scholar]
  3. Baumert, T. F., Marrone, A., Vergalla, J. & Liang, T. J.(1998). Naturally occurring mutations define a novel function of the hepatitis B virus core promoter in core protein expression. J Virol 72, 6785–6795. [Google Scholar]
  4. Blum, H. E., Zhang, Z. S., Galun, E., von Weizsacker, F., Garner, B., Liang, T. J. & Wands, J. R.(1992). Hepatitis B virus X protein is not central to the viral life cycle in vitro. J Virol 66, 1223–1227. [Google Scholar]
  5. Bouchard, M. J. & Schneider, R. J.(2004). The enigmatic X gene of hepatitis B virus. J Virol 78, 12725–12734.[CrossRef] [Google Scholar]
  6. Bouchard, M. J., Wang, L. H. & Schneider, R. J.(2001). Calcium signaling by HBx protein in hepatitis B virus DNA replication. Science 294, 2376–2378.[CrossRef] [Google Scholar]
  7. Buckwold, V. E., Xu, Z., Chen, M., Yen, T. S. & Ou, J. H.(1996). Effects of a naturally occurring mutation in the hepatitis B virus basal core promoter on precore gene expression and viral replication. J Virol 70, 5845–5851. [Google Scholar]
  8. Buckwold, V. E., Xu, Z., Yen, T. S. & Ou, J. H.(1997). Effects of a frequent double-nucleotide basal core promoter mutation and its putative single-nucleotide precursor mutations on hepatitis B virus gene expression and replication. J Gen Virol 78, 2055–2065. [Google Scholar]
  9. Cha, M.-Y., Ryu, D.-K., Jung, H.-S., Chang, H.-E. & Ryu, W.-S.(2009). Stimulation of hepatitis B virus genome replication by HBx is linked to both nuclear and cytoplasmic HBx expression. J Gen Virol 90, 978–986.[CrossRef] [Google Scholar]
  10. Chomczynski, P. & Sacchi, N.(1987). Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem 162, 156–159. [Google Scholar]
  11. Gunther, S., Fischer, L., Pult, I., Sterneck, M. & Will, H.(1999). Naturally occurring variants of hepatitis B virus. Adv Virus Res 52, 25–137. [Google Scholar]
  12. Guo, X., Jin, Y., Qian, G. & Tu, H.(2008). Sequential accumulation of the mutations in core promoter of hepatitis B virus is associated with the development of hepatocellular carcinoma in Qidong, China. J Hepatol 49, 718–725.[CrossRef] [Google Scholar]
  13. Jammeh, S., Tavner, F., Watson, R., Thomas, H. C. & Karayiannis, P.(2008). Effect of basal core promoter and pre-core mutations on hepatitis B virus replication. J Gen Virol 89, 901–909.[CrossRef] [Google Scholar]
  14. Jeong, J. K., Yoon, G. S. & Ryu, W. S.(2000). Evidence that the 5′-end cap structure is essential for encapsidation of hepatitis B virus pregenomic RNA. J Virol 74, 5502–5508.[CrossRef] [Google Scholar]
  15. Kao, J. H., Chen, P. J., Lai, M. Y. & Chen, D. S.(2003). Basal core promoter mutations of hepatitis B virus increase the risk of hepatocellular carcinoma in hepatitis B carriers. Gastroenterology 124, 327–334.[CrossRef] [Google Scholar]
  16. Lee, J., Lee, H.-J., Shin, M.-K. & Ryu, W.-S.(2004). Versatile PCR-mediated insertion or deletion mutagenesis. Biotechniques 36, 398–400. [Google Scholar]
  17. Li, J., Buckwold, V. E., Hon, M. W. & Ou, J. H.(1999). Mechanism of suppression of hepatitis B virus precore RNA transcription by a frequent double mutation. J Virol 73, 1239–1244. [Google Scholar]
  18. Lim, S. G., Cheng, Y., Guindon, S., Seet, B. L., Lee, L. Y., Hu, P., Wasser, S., Peter, F. J., Tan, T. & other authors(2007). Viral quasi-species evolution during hepatitis B e antigen seroconversion. Gastroenterology 133, 951–958.[CrossRef] [Google Scholar]
  19. Liu, C. J., Chen, B. F., Chen, P. J., Lai, M. Y., Huang, W. L., Kao, J. H. & Chen, D. S.(2006). Role of hepatitis B viral load and basal core promoter mutation in hepatocellular carcinoma in hepatitis B carriers. J Infect Dis 193, 1258–1265.[CrossRef] [Google Scholar]
  20. Malmassari, S. L., Deng, Q., Fontaine, H., Houitte, D., Rimlinger, F., Thiers, V., Maillere, B., Pol, S. & Michel, M. L.(2007). Impact of hepatitis B virus basic core promoter mutations on T cell response to an immunodominant HBx-derived epitope. Hepatology 45, 1199–1209.[CrossRef] [Google Scholar]
  21. Melegari, M., Scaglioni, P. P. & Wands, J. R.(1998). Cloning and characterization of a novel hepatitis B virus x binding protein that inhibits viral replication. J Virol 72, 1737–1743. [Google Scholar]
  22. Melegari, M., Wolf, S. K. & Schneider, R. J.(2005). Hepatitis B virus DNA replication is coordinated by core protein serine phosphorylation and HBx expression. J Virol 79, 9810–9820.[CrossRef] [Google Scholar]
  23. Moriyama, K., Okamoto, H., Tsuda, F. & Mayumi, M.(1996). Reduced precore transcription and enhanced core-pregenome transcription of hepatitis B virus DNA after replacement of the precore-core promoter with sequences associated with e antigen-seronegative persistent infections. Virology 226, 269–280.[CrossRef] [Google Scholar]
  24. Okamoto, H., Tsuda, F., Akahane, Y., Sugai, Y., Yoshiba, M., Moriyama, K., Tanaka, T., Miyakawa, Y. & Mayumi, M.(1994). Hepatitis B virus with mutations in the core promoter for an e antigen-negative phenotype in carriers with antibody to e antigen. J Virol 68, 8102–8110. [Google Scholar]
  25. Parekh, S., Zoulim, F., Ahn, S. H., Tsai, A., Li, J., Kawai, S., Khan, N., Trepo, C., Wands, J. & Tong, S.(2003). Genome replication, virion secretion, and e antigen expression of naturally occurring hepatitis B virus core promoter mutants. J Virol 77, 6601–6612.[CrossRef] [Google Scholar]
  26. Pugh, J. C., Yaginuma, K., Koike, K. & Summers, J.(1988). Duck hepatitis B virus (DHBV) particles produced by transient expression of DHBV DNA in a human hepatoma cell line are infectious in vitro. J Virol 62, 3513–3516. [Google Scholar]
  27. Ryu, D. K., Kim, S. & Ryu, W. S.(2008). Hepatitis B virus polymerase suppresses translation of pregenomic RNA via a mechanism involving its interaction with 5′ stem–loop structure. Virology 373, 112–123.[CrossRef] [Google Scholar]
  28. Scaglioni, P. P., Melegari, M. & Wands, J. R.(1997). Biologic properties of hepatitis B viral genomes with mutations in the precore promoter and precore open reading frame. Virology 233, 374–381.[CrossRef] [Google Scholar]
  29. Seeger, C., Zoulim, F. & Mason, W.(2007). Hepadnaviruses. In Fields Virology, 5th edn, pp. 2977–3029. Edited by D. M. Knipe & P. M. Howley. Philadelphia, PA: Lippincott Williams and Wilkins.
  30. Shin, M.-K., Lee, J. & Ryu, W.-S.(2004). A novel cis-acting element facilitates minus-strand DNA synthesis during reverse transcription of the hepatitis B virus genome. J Virol 78, 6252–6262.[CrossRef] [Google Scholar]
  31. Tang, H., Delgermaa, L., Huang, F., Oishi, N., Liu, L., He, F., Zhao, L. & Murakami, S.(2005). The transcriptional transactivation function of HBx protein is important for its augmentation role in hepatitis B virus replication. J Virol 79, 5548–5556.[CrossRef] [Google Scholar]
  32. Yim, H. J. & Lok, A. S.(2006). Natural history of chronic hepatitis B virus infection: what we knew in 1981 and what we know in 2005. Hepatology 43, S173–S181.[CrossRef] [Google Scholar]
  33. Zheng, Y., Li, J. & Ou, J. H.(2004). Regulation of hepatitis B virus core promoter by transcription factors HNF1 and HNF4 and the viral X protein. J Virol 78, 6908–6914.[CrossRef] [Google Scholar]
  34. Zoulim, F., Saputelli, J. & Seeger, C.(1994). Woodchuck hepatitis virus X protein is required for viral infection in vivo. J Virol 68, 2026–2030. [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/vir.0.010421-0
Loading
/content/journal/jgv/10.1099/vir.0.010421-0
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error