Rotavirus translation

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Comparison of cellular translation (above) and Rotaviral translation (below) Rotavirus Translation.svg
Comparison of cellular translation (above) and Rotaviral translation (below)

Rotavirus translation, the process of translating mRNA into proteins, occurs in a different way in Rotaviruses. Unlike the vast majority of cellular proteins in other organisms, in Rotaviruses the proteins are translated from capped but nonpolyadenylated mRNAs. The viral nonstructural protein NSP3 specifically binds the 3'-end consensus sequence of viral mRNAs and interacts with the eukaryotic translation initiation factor eIF4G. The Rotavirus replication cycle occurs entirely in the cytoplasm. Upon virus entry, the viral transcriptase synthesizes capped but nonpolyadenylated mRNA The viral mRNAs bear 5' and 3' untranslated regions (UTR) of variable length and are flanked by two different sequences common to all genes.

In the group A rotaviruses, the 3'-end consensus sequence UGACC is highly conserved among the 11 genes. Rotavirus NSP3 presents several similarities to PABP; in rotavirus-infected cells, NSP3 can be cross-linked to the 3' end of rotavirus mRNAs and is coimmunoprecipitated with eIF4G. The binding of NSP3A to eIF4G and its specific interaction with the 3' end of viral mRNA brings the viral mRNA and the translation initiation machinery into contact, thus favoring efficient translation of the viral mRNA. NSP3 interacts with the same region of eIF4G as PABP does. As a consequence, during rotavirus infection PABP is evicted from eIF4G, probably impairing the translation of polyadenylated mRNA and leading to the shutoff of cellular mRNA translation observed during rotavirus infection. [1] [2]

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<span class="mw-page-title-main">Poly(A)-binding protein</span> RNA binding protein

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<span class="mw-page-title-main">NSP3 (rotavirus)</span>

Rotavirus protein NSP3 (NS34) is bound to the 3' end consensus sequence of viral mRNAs in infected cells.

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<span class="mw-page-title-main">Eukaryotic translation initiation factor 4 gamma 1</span>

Eukaryotic translation initiation factor 4 gamma 1 is a protein that in humans is encoded by the EIF4G1 gene.

<span class="mw-page-title-main">EIF4A1</span> Protein coding gene in Humans

Eukaryotic initiation factor 4A-I is a 46 kDa cytosolic protein that, in humans, is encoded by the EIF4A1 gene, which is located on chromosome 17. It is the most prevalent member of the eIF4A family of ATP-dependant RNA helicases, and plays a critical role in the initiation of cap-dependent eukaryotic protein translation as a component of the eIF4F translation initiation complex. eIF4A1 unwinds the secondary structure of RNA within the 5'-UTR of mRNA, a critical step necessary for the recruitment of the 43S preinitiation complex, and thus the translation of protein in eukaryotes. It was first characterized in 1982 by Grifo, et al., who purified it from rabbit reticulocyte lysate.

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<span class="mw-page-title-main">Eukaryotic initiation factor 4F</span> Multiprotein complex used in gene expression

Eukaryotic initiation factor 4F (eIF4F) is a heterotrimeric protein complex that binds the 5' cap of messenger RNAs (mRNAs) to promote eukaryotic translation initiation. The eIF4F complex is composed of three non-identical subunits: the DEAD-box RNA helicase eIF4A, the cap-binding protein eIF4E, and the large "scaffold" protein eIF4G. The mammalian eIF4F complex was first described in 1983, and has been a major area of study into the molecular mechanisms of cap-dependent translation initiation ever since.

References

  1. Poncet, Didier; Carlos Aponte; Jean Cohen (June 1993). "Rotavirus protein NSP3 (NS34) is bound to the 3' end consensus sequence of viral mRNAs in infected cells". J Virol. 67 (6): 3159–3165. doi:10.1128/JVI.67.6.3159-3165.1993. PMC   237654 . PMID   8388495.
  2. Piron, Maria; Patrice Vende; Jean Cohen; Didier Poncet (1998). "Rotavirus RNA-binding protein NSP3 interacts with eIF4GI and evicts the poly(A) binding protein from eIF4F". EMBO Journal. 17 (19): 5811–21. doi:10.1093/emboj/17.19.5811. PMC   1170909 . PMID   9755181.