Translation of Poliovirus mRNA

Abstract

Ribosome binding to cellular eukaryotic mRNAs is proposed to occur by initial attachment at or near the mRNA 5' cap structure (m^7 GpppN, where N is any nucleotide) followed by scanning till the appropriate initiator AUG is encountered. A pivotal aspect of this model is the obligatory entry of the ribosomes at the 5' end of the mRNA (regardless if it contains a cap structure). Recent experiments, however, demonstrated that ribosomes can access certain mRNAs by internal binding to the 5'-untranslated region. This was most clearly demonstrated for members of the picornavirus family such as poliovirus and encephalomyocarditis virus. Further experiments suggest that other viral mRNAs and even cellular mRNAs may use similar mechanisms of ribosome binding. Here we describe some features of the poliovirus 5'-untranslated region and possible trans-acting factors that are involved in this mechanism of translation.

AXenopus laevisHomologue of the La Autoantigen Binds the Pyrimidine Tract of the 5′ UTR of Ribosomal Protein mRNAsin Vitro: Implication of a Protein Factor in Complex Formation

“…Interestingly, the protein p52, which binds to the poliovirus RNA 5' UTR (Sonenberg & Meerovitch, 1990) has been recently identified as La (Meerovitch et al, 1993;. This host cell protein interacts with a region of the viral RNA that includes the highly conserved and functionally important pyrimidine motif involved in internal initiation of translation of the poliovirus RNA.…”

Bioinformatics and Drug Discovery

“…The first is whether the translation machinery starts scanning for the start codon from the 5' end of mRNA [191,192] or from internal ribosome entry sites [169,[193][194][195][196]. The second is whether the small ribosomal subunit does the scanning for the start codon or a fully formed ribosome can also perform the scan.…”

Expression of the coat protein of potato virus X from a dicistronic mRNA in transgenic potato plants.

“…Among the most extensively studied is poliovirus RNA, which can be translated in infected cells that have lost their ability to initiate cap-dependent translation (Pelletier & Sonenberg, 1985 ;Sonenberg & Meerovitch, 1990). The specific region responsible for internal initiation of translation in poliovirus has been identified and is a site for preferential ribosome binding (Pelletier et al, 1988 ; Author for correspondence : Mounir G. AbouHaidar.…”