Open AccessCap-independent translation of poliovirus mRNA is conferred by sequence elements within the 5' noncoding region.
Author(s) -
Jerry Pelletier,
Gerardo Kaplan,
Vincent R. Racaniello,
Nahum Sonenberg
Publication year - 1988
Publication title -
molecular and cellular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.14
H-Index - 327
eISSN - 1067-8824
pISSN - 0270-7306
DOI - 10.1128/mcb.8.3.1103
Subject(s) - biology , poliovirus , messenger rna , translation (biology) , rna , internal ribosome entry site , ribosome , polysome , microbiology and biotechnology , protein biosynthesis , genetics , virus , gene
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.