Rubella virus capsid protein modulation of viral genomic and subgenomic RNA synthesis

Journal Article · Tue Jul 05 04:00:00 EDT 2005 · Virology

DOI:https://doi.org/10.1016/j.virol.2005.04.019· OSTI ID:20726041

Tzeng, W -P ^[1]; Frey, Teryl K ^[1]

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1. Department of Biology, Georgia State University, PO Box 4010, Atlanta, GA 30302-4010 (United States)

The ratio of the subgenomic (SG) to genome RNA synthesized by rubella virus (RUB) replicons expressing the green fluorescent protein reporter gene (RUBrep/GFP) is substantially higher than the ratio of these species synthesized by RUB (4.3 for RUBrep/GFP vs. 1.3-1.4 for RUB). It was hypothesized that this modulation of the viral RNA synthesis was by one of the virus structural protein genes and it was found that introduction of the capsid (C) protein gene into the replicons as an in-frame fusion with GFP resulted in an increase of genomic RNA production (reducing the SG/genome RNA ratio), confirming the hypothesis and showing that the C gene was the moiety responsible for the modulation effect. The N-terminal one-third of the C gene was required for the effect of be exhibited. A similar phenomenon was not observed with the replicons of Sindbis virus, a related Alphavirus. Interestingly, modulation was not observed when RUBrep/GFP was co-transfected with either other RUBrep or plasmid constructs expressing the C gene, demonstrating that modulation could occur only when the C gene was provided in cis. Mutations that prevented translation of the C protein failed to modulate RNA synthesis, indicating that the C protein was the moiety responsible for modulation; consistent with this conclusion, modulation of RNA synthesis was maintained when synonymous codon mutations were introduced at the 5' end of the C gene that changed the C gene sequence without altering the amino acid sequence of the C protein. These results indicate that C protein translated in proximity of viral replication complexes, possibly from newly synthesized SG RNA, participate in regulating the replication of viral RNA.

• OSTI ID: 20726041
• Journal Information: Virology, Journal Name: Virology Journal Issue: 2 Vol. 337; ISSN VIRLAX; ISSN 0042-6822
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AMINO ACID SEQUENCE
BIOSYNTHESIS
MEASLES VIRUS
MUTATIONS
PROTEINS
REPLICONS
RNA