The position 4 nucleotide at the 3' end of the influenza virus neuraminidase vRNA is involved in temporal regulation of transcription and replication of neuraminidase RNAs and affects the repertoire of influenza virus surface antigens.

Lee, Kwang Hee; Seong, Baik Lin

doi:10.1099/0022-1317-79-8-1923

Cited by 30 publications

(29 citation statements)

References 48 publications

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“…2a). It is believed that the low mRNA : cRNA ratios characteristic of the three polymerase gene segments during viral infection, compared with the high mRNA : cRNA ratios of the nonpolymerase gene segments, are caused by a single nucleotide change at position 4 of the 39 end of the vRNA promoter, which is a C residue in the polymerase genes but a U residue in most of the non-polymerase gene segments (Lee & Seong, 1998;Lee et al, 2003). However, in RNP reconstitution assays, we have observed high mRNA : cRNA ratios for the polymerase genes (see Figs 1 and 3), which suggests that the nature of the residue at position 4 alone is not sufficient to determine mRNA : cRNA ratios.…”

Section: Discussionmentioning

confidence: 99%

NS2/NEP protein regulates transcription and replication of the influenza virus RNA genome

Robb

Smith

Vreede

et al. 2009

Journal of General Virology

195

192

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The influenza virus RNA polymerase transcribes the negative-sense viral RNA segments (vRNA) into mRNA and replicates them via complementary RNA (cRNA) intermediates into more copies of vRNA. It is not clear how the relative amounts of the three RNA products, mRNA, cRNA and vRNA, are regulated during the viral life cycle. We found that in viral ribonucleoprotein (vRNP) reconstitution assays involving only the minimal components required for viral transcription and replication (the RNA polymerase, the nucleoprotein and a vRNA template), the relative levels of accumulation of RNA products differed from those observed in infected cells, suggesting a regulatory role for additional viral proteins. Expression of the viral NS2/NEP protein in RNP reconstitution assays affected viral RNA levels by reducing the accumulation of transcription products and increasing the accumulation of replication products to more closely resemble those found during viral infection. This effect was functionally conserved in influenza A and B viruses and was influenza-virus-type-specific, demonstrating that the NS2/NEP protein changes RNA levels by specific alteration of the viral transcription and replication machinery, rather than through an indirect effect on the host cell. Although NS2/NEP has been shown previously to play a role in the nucleocytoplasmic export of viral RNPs, deletion of the nuclear export sequence region that is required for its transport function did not affect the ability of the protein to regulate RNA levels. A role for the NS2/NEP protein in the regulation of influenza virus transcription and replication that is independent of its viral RNP export function is proposed.

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Section: Discussionmentioning

confidence: 99%

NS2/NEP protein regulates transcription and replication of the influenza virus RNA genome

Robb

Smith

Vreede

et al. 2009

Journal of General Virology

195

192

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“…The 3-methoxiphenol liberated [22] and the enzyme activity was measured by OD readings taken from the part of the slope where they vary linearly with the enzyme concentration.…”

Section: Substrate Specificity and Kinetic Datamentioning

confidence: 99%

Characterization of Sialidase from an Influenza A (H3N2) Virus Strain: Kinetic Parameters and Substrate Specificity

Barros

Alviano²,

Silva³

et al. 2003

Intervirology

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Neuraminidase (NA) of influenza A (H3N2) viruses was characterized after purification by gel filtration and proteolytic treatment, using the X-31 variant strain that is a reassortment between the influenza A/Victoria/3/75 (responsible for the 1975 pandemic) and the influenza A/PR/8/34 virus samples, as a model. In the purification process, NA heads, that is the spike responsible for the virus sialidase activity, were purified by filtration through a Bio-Gel polyacrylamide column. The enzyme activity was determined by periodic acid/thiobarbituric acid assay and high-performance thin-layer chromatography. The sialidase showed preference for the α-2,3-linkage over the α-2,6-linkage of sialyllactoses (K_m of 1.8 and 5.2 × 10^–4M, respectively) at pH 5.2. The enzyme acted on natural and synthetic substrates at different hydrolysis rates, as well as on human erythrocytes (A group, Rh+) and yeast (Candida albicans) cells. The active NA produced by gel filtration was characterized by different parameters of its sialidase activity, also showing to be a suitable tool for the identification of natural sialocompounds and for the screening of antisialidase drugs to treat influenza virus infections.

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“…The only known variation (U/C) occurs at position 4 at the 3Ј terminus (Fig. 1B, , and this variation is involved in differential gene expression (3,13). In contrast to multiplex RT-PCR strategies that use multiple primer pairs (2), our initial strategy uses one pair of primers to amplify all of the vRNAs.…”

mentioning

confidence: 99%

Single-Reaction Genomic Amplification Accelerates Sequencing and Vaccine Production for Classical and Swine Origin Human Influenza A Viruses

Zhou

Donnelly

Scholes

et al. 2009

J Virol

556

501

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Pandemic influenza A viruses that emerge from animal reservoirs are inevitable. Therefore, rapid genomic analysis and creation of vaccines are vital. We developed a multisegment reverse transcription-PCR (M-RTPCR) approach that simultaneously amplifies eight genomic RNA segments, irrespective of virus subtype. M-RTPCR amplicons can be used for high-throughput sequencing and/or cloned into modified reverse-genetics plasmids via regions of sequence identity. We used these procedures to rescue a contemporary H3N2 virus and a swine origin H1N1 virus directly from human swab specimens. Together, M-RTPCR and the modified reverse-genetics plasmids that we designed streamline the creation of vaccine seed stocks (9 to 12 days).

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The position 4 nucleotide at the 3' end of the influenza virus neuraminidase vRNA is involved in temporal regulation of transcription and replication of neuraminidase RNAs and affects the repertoire of influenza virus surface antigens.

Cited by 30 publications

References 48 publications

NS2/NEP protein regulates transcription and replication of the influenza virus RNA genome

NS2/NEP protein regulates transcription and replication of the influenza virus RNA genome

Characterization of Sialidase from an Influenza A (H3N2) Virus Strain: Kinetic Parameters and Substrate Specificity

Single-Reaction Genomic Amplification Accelerates Sequencing and Vaccine Production for Classical and Swine Origin Human Influenza A Viruses

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