1887

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Volume 89, Issue 1

Differences in the expression of the hepatitis C virus core+1 open reading frame between a nuclear and a cytoplasmic expression system Free

Abstract

The hepatitis C virus (HCV) genome possesses an open reading frame (ORF) overlapping the core gene at +1 nucleotide (core+1 ORF). Initial studies suggested that the core+1 ORF is translated by a ribosomal −2/+1 frameshift mechanism during elongation of the viral polyprotein. Recent studies, however, based on transfection of mammalian cells with reporter constructs have shown that translation of the core+1 ORF is mediated from internal core+1 codons. To resolve the apparent discrepancies associated with the mechanism of core+1 translation, we examined the expression of the HCV-1 and HCV-1a (H) core+1 ORF in a cytoplasmic transcription system based on Huh-7/T7 cells that constitutively synthesize the T7 RNA polymerase in comparison to that in Huh-7 cells. We showed that the efficiency of both the −2/+1 and −1/+2 frameshift events operating at the HCV-1 core codons 8–11 is significantly enhanced in the Huh-7/T7 cytoplasmic transcription system and is dependent on the presence of the consecutive adenine (A) residues within core codons 8–11. In contrast, internal translation initiation at core+1 codons 85/87 occurs in both the nuclear and cytoplasmic transcription systems and is not repressed by the ribosomal frameshifting event. Finally, although core+1 codons 85/87 is the most efficient site for internal initiation of core+1 translation, it may not be unique, as additional internal core+1 codon(s) appear to drive translation at low levels.

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  • Accepted:
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2008-01-01
2024-09-20
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References

  1. Bain C., Parroche P., Lavergne J. P., Duverger B., Vieux C., Dubois V., Komurian-Pradel F., Trépo C., Gebuhrer L. other authors 2004; Memory T-cell-mediated immune responses specific to an alternative core protein in hepatitis C virus infection. J Virol 78:10460–10469 [CrossRef]
     [Google Scholar]
  2. Baril M., Brakier-Gingras L. 2005; Translation of the F protein of hepatitis C virus is initiated at a non-AUG codon in a +1 reading frame relative to the polyprotein. Nucleic Acids Res 33:1474–1486 [CrossRef]
     [Google Scholar]
  3. Boulant S., Ratinier M., Hope G., McLauchlan J., Inchauspe G., Descollonges Y., Penin F., Lavergne J. P. 2003; Characterization and use of a monoclonal antibody to detect hepatitis C virus F protein. 10th International Meeting on Hepatitis C Virus and Related Viruses. Molecular Virology and Pathogenesis Kyoto, Japan:
     [Google Scholar]
  4. Branch A. D., Walewski J. L., Gutierrez J. A. other authors 2003; HCV alternate reading frame proteins (ARFPs) may be virulence factors that help the virus survive adverse conditions. Hepatology 38:468A–469A
     [Google Scholar]
  5. Choi J., Xu Z., Ou J. H. 2003; Triple decoding of hepatitis C virus RNA by programmed translational frameshifting. Mol Cell Biol 23:1489–1497 [CrossRef]
     [Google Scholar]
  6. Choo Q. L., Kuo G., Weiner A. J., Overby L. R., Bradley D. W., Houghton M. 1989; Isolation of a cDNA clone derived from a blood-borne non-A, non-B viral hepatitis genome. Science 244:359–362 [CrossRef]
     [Google Scholar]
  7. Fang J. W., Moyer R. W. 2000; The effects of the conserved extreme 3′ end sequence of hepatitis C virus (HCV) RNA on the in vitro stabilization and translation of the HCV RNA genome. J Hepatol 33:632–639 [CrossRef]
     [Google Scholar]
  8. Harlow E. a. L. D. 1988 Antibodies. A Laboratory Manual Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
     [Google Scholar]
  9. Hoofnagle J. H. 2002; Course and outcome of hepatitis C. Hepatology 36:S21–S29
     [Google Scholar]
  10. Ina Y., Mizokami M., Ohba K., Gojobori T. 1994; Reduction of synonymous substitutions in the core protein gene of hepatitis C virus. J Mol Evol 38:50–56
     [Google Scholar]
  11. Kalamvoki M., Mavromara P. 2004; Calcium-dependent calpain proteases are implicated in processing of the hepatitis C virus NS5A protein. J Virol 78:11865–11878 [CrossRef]
     [Google Scholar]
  12. Komurian-Pradel F., Rajoharison A., Berland J. L., Khouri V., Perret M., Van Roosmalen M., Pol S., Negro F., Paranhos-Baccala G. 2004; Antigenic relevance of F protein in chronic hepatitis C virus infection. Hepatology 40:900–909 [CrossRef]
     [Google Scholar]
  13. Lindenbach B. D., Rice C. M. 2005; Unravelling hepatitis C virus replication from genome to function. Nature 436:933–938 [CrossRef]
     [Google Scholar]
  14. Meskauskas A., Harger J. W., Jacobs K. L., Dinman J. D. 2003; Decreased peptidyltransferase activity correlates with increased programmed −1 ribosomal frameshifting and viral maintenance defects in the yeast Saccharomyces cerevisiae . RNA 9:982–992 [CrossRef]
     [Google Scholar]
  15. Meskauskas A., Petrov A. N., Dinman J. D. 2005; Identification of functionally important amino acids of ribosomal protein L3 by saturation mutagenesis. Mol Cell Biol 25:10863–10874 [CrossRef]
     [Google Scholar]
  16. Muldoon-Jacobs K. L., Dinman J. D. 2006; Specific effects of ribosome-tethered molecular chaperones on programmed −1 ribosomal frameshifting. Eukaryot Cell 5:762–770 [CrossRef]
     [Google Scholar]
  17. Penin F., Dubuisson J., Rey F. A., Moradpour D., Pawlotsky J. M. 2004; Structural biology of hepatitis C virus. Hepatology 39:5–19 [CrossRef]
     [Google Scholar]
  18. Rice C. M. 2003; HCV life cycle and targets for drug development. Hepatitis Annual Update123–142
     [Google Scholar]
  19. Smith D. B., Simmonds P. 1997; Characteristics of nucleotide substitution in the hepatitis C virus genome: constraints on sequence change in coding regions at both ends of the genome. J Mol Evol 45:238–246 [CrossRef]
     [Google Scholar]
  20. Song Y., Friebe P., Tzima E., Junemann C., Bartenschlager R., Niepmann M. 2006; The hepatitis C virus RNA 3′-untranslated region strongly enhances translation directed by the internal ribosome entry site. J Virol 80:11579–11588 [CrossRef]
     [Google Scholar]
  21. Varaklioti A., Vassilaki N., Georgopoulou U., Mavromara P. 2002; Alternate translation occurs within the core coding region of the hepatitis C viral genome. J Biol Chem 277:17713–17721 [CrossRef]
     [Google Scholar]
  22. Vassilaki N., Mavromara P. 2003; Two alternative translation mechanisms are responsible for the expression of the HCV ARFP/F/core+1 coding open reading frame. J Biol Chem 278:40503–40513 [CrossRef]
     [Google Scholar]
  23. Walewski J. L., Keller T. R., Stump D. D., Branch A. D. 2001; Evidence for a new hepatitis C virus antigen encoded in an overlapping reading frame. RNA 7:710–721 [CrossRef]
     [Google Scholar]
  24. Xu Z., Choi J., Yen T. S., Lu W., Strohecker A., Govindarajan S., Chien D., Selby M. J., Ou J. 2001; Synthesis of a novel hepatitis C virus protein by ribosomal frameshift. EMBO J 20:3840–3848 [CrossRef]
     [Google Scholar]
  25. Zoulim F., Chevallier M., Maynard M., Trepo C. 2003; Clinical consequences of hepatitis C virus infection. Rev Med Virol 13:57–68 [CrossRef]
     [Google Scholar]
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Differences in the expression of the hepatitis C virus core+1 open reading frame between a nuclear and a cytoplasmic expression system
J. Gen. Virol. 89, 222 (2008); https://doi.org/10.1099/vir.0.83260-0
/content/journal/jgv/10.1099/vir.0.83260-0
/content/journal/jgv/10.1099/vir.0.83260-0
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