HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Supplementary Table Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Vassilaki, N. Articles by Mavromara, P. Search for Related Content PubMed PubMed Citation Articles by Vassilaki, N. Articles by Mavromara, P. Agricola Articles by Vassilaki, N. Articles by Mavromara, P.

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

Molecular Virology Laboratory, Hellenic Pasteur Institute, 127 Vas. Sofias Avenue, Athens 11521, Greece

Correspondence
Penelope Mavromara
penelopm{at}hol.gr

The hepatitis C virus (HCV) genome possesses an open reading frame (ORF) overlapping the core gene at +1 nucleotide (core+1 ORF). Initial in vitro 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.

The primer sequences for the insertion of mutation N25 in the HCV-1a (H) sequence and also for N27–N29 and N30 are described in Supplementary Table S1 available with the online version of this paper.

This article has been cited by other articles:

				N. Vassilaki, P. Friebe, P. Meuleman, S. Kallis, A. Kaul, G. Paranhos-Baccala, G. Leroux-Roels, P. Mavromara, and R. Bartenschlager Role of the Hepatitis C Virus Core+1 Open Reading Frame and Core cis-Acting RNA Elements in Viral RNA Translation and Replication J. Virol., December 1, 2008; 82(23): 11503 - 11515. [Abstract] [Full Text] [PDF]