Poliovirus translation: A paradigm for a novel initiation mechanism

✍ Scribed by Nahum Sonenberg; Jerry Pelletier

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 645 KB
• Volume: 11
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/bies.950110504

✦ Synopsis

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.