A functional cis-acting element between nucleotides 320 and 631 of the 5' noncoding region of poliovirus mRNA enables cap-independent translation.
Identifies the specific 5' noncoding region (nucleotides 320-631) responsible for cap-independent translation of poliovirus mRNA.
Poliovirus polysomal RNA is naturally uncapped, and as such, its translation must bypass any 5' cap-dependent ribosome recognition event. To elucidate the manner by which poliovirus mRNA is translated, we have determined the translational efficiencies of a series of deletion mutants within the 5' noncoding region of the mRNA. We found striking differences in translatability among the altered mRNAs when assayed in mock-infected and poliovirus-infected HeLa cell extracts. The results identify a functional cis-acting element within the 5' noncoding region of the poliovirus mRNA which enables it to translate in a cap-independent fashion. The major determinant of this element maps between nucleotides 320 and 631 of the 5' end of the poliovirus mRNA. We also show that this region (320 to 631), when fused to a heterologous mRNA, can function in cis to render the mRNA cap independent in translation.
Pelletier et al. (Tue,) conducted a other in Poliovirus infection. Deletion mutants within the 5' noncoding region of poliovirus mRNA vs. Wild-type or other mutants was evaluated on Translational efficiency in HeLa cell extracts. A functional cis-acting element between nucleotides 320 and 631 of the 5' noncoding region of poliovirus mRNA enables cap-independent translation.