Poliovirus translation: a paradigm for a novel initiation mechanism.
All eukaryotic cellular mRNAs, and most viral mRNAs, are blocked at their 5' ends with a cap structure (m7GpppX, where X is any nucleotide). Poliovirus, along with a small number of other animal and plant viral mRNAs, does not contain a 5' cap structure. Since the cap structure functions to facilitate ribosome binding to mRNA, translation of polio-virus must proceed by a cap-independent mechanism. Consistent with this, recent studies have shown that ribosomes can bind to an internal region within the long 5' noncoding sequence of poliovirus RNA. Possible mechanisms for cap-independent translation are discussed. Cap-independent translation of poliovirus RNA is of major importance to the mechanism of shut-off of host protein synthesis after infection. Moreover, it is likely to play a role in determining poliovirus neurovirulence and attenuation.
Sonenberg
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N
Pelletier
J
J
D006801:Humans; D007152:Immunologic Capping / Q000502:physiology; D008957:Models, Genetic; D010448:Peptide Initiation Factors / Q000235:genetics; D017955:Poliovirus / Q000235:genetics* / Q000472:pathogenicity; D014176:Protein Biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*
D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012367:RNA, Viral