To maintain genome integrity, segmented double-stranded RNA viruses of the Reoviridae family must accurately select and package a complete set of up to a dozen distinct genomic RNAs. It is thought that the high fidelity segmented genome assembly involves multiple sequence-specific RNA-RNA interactions between single-stranded RNA segment precursors. These are mediated by virus-encoded non-structural proteins with RNA chaperone-like activities, such as rotavirus (RV) NSP2 and avian reovirus σNS. Here, we compared the abilities of NSP2 and σNS to mediate sequence-specific interactions between RV genomic segment precursors. Despite their similar activities, NSP2 successfully promotes inter-segment association, while σNS fails to do so. To understand the mechanisms underlying such selectivity in promoting inter-molecular duplex formation, we compared RNA-binding and helix-unwinding activities of both proteins. We demonstrate that octameric NSP2 binds structured RNAs with high affinity, resulting in efficient intramolecular RNA helix disruption. Hexameric σNS oligomerizes into an octamer that binds two RNAs, yet it exhibits only limited RNA-unwinding activity compared to NSP2. Thus, the formation of intersegment RNA-RNA interactions is governed by both helix-unwinding capacity of the chaperones and stability of RNA structure. We propose that this protein-mediated RNA selection mechanism may underpin the high fidelity assembly of multi-segmented RNA genomes in Reoviridae.
- MeSH
- genom virový genetika MeSH
- konformace nukleové kyseliny MeSH
- molekulární chaperony chemie genetika metabolismus MeSH
- molekulární modely MeSH
- proteiny vázající RNA chemie genetika metabolismus MeSH
- ptačí orthoreovirus genetika metabolismus MeSH
- RNA virová chemie genetika metabolismus MeSH
- sekundární struktura proteinů MeSH
- sekvence nukleotidů MeSH
- vazba proteinů MeSH
- virové nestrukturální proteiny chemie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Oncolytic virotherapy is a novel approach to cancer treatment. In the present study we tested the ability of reovirus type 3, strain Dearing, to suppress the growth of tumors induced in mice by HPV16-transformed TC-1 cells. In vitro, these cells are highly susceptible to the virus. In repeated in vivo tests the intratumoral inoculation of the virus resulted in only a minor slow-down of tumor growth, never in a complete cure. The effect of the treatment was not enhanced by the simultaneous administration of non-oncogenic, genetically modified TC-1 cells expressing either IL-2, IL-12 or GM-CSF, and, in fact, the oncolytic effect of the virus was even less expressed in some instances. When cyclophosphamide was used in combination with the viral treatment, a synergistic effect resulting in tumor suppression was observed. In most instances the tumor regression was transitory, however, and was followed by tumor progression. The outcome of these experiments was dependent on the timing of the two treatments.
- MeSH
- cyklofosfamid aplikace a dávkování MeSH
- experimentální nádory terapie virologie MeSH
- faktor stimulující granulocyto-makrofágové kolonie genetika MeSH
- financování organizované MeSH
- genetická terapie metody MeSH
- interleukin-12 genetika MeSH
- interleukin-2 genetika MeSH
- kombinovaná terapie MeSH
- lidský papilomavirus 16 MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- onkolytická viroterapie metody MeSH
- protinádorové látky aplikace a dávkování MeSH
- protinádorové vakcíny aplikace a dávkování MeSH
- savčí orthoreovirus 3 MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
Wageningen UR frontis series ; vol. 8
vii, 152 s. : tab. ; 24 cm
- MeSH
- Alphainfluenzavirus patogenita MeSH
- Betainfluenzavirus patogenita MeSH
- chřipka lidská prevence a kontrola MeSH
- epidemický výskyt choroby prevence a kontrola MeSH
- ptačí chřipka u ptáků prevence a kontrola MeSH
- ptačí orthoreovirus MeSH
- vakcíny proti chřipce MeSH
- virus chřipky A, podtyp H5N1 patogenita MeSH
- zoonózy MeSH
- Publikační typ
- sborníky MeSH
- Konspekt
- Virologie
- NLK Obory
- virologie
- epidemiologie
- alergologie a imunologie
