A cellular protein that binds to the 5'-noncoding region of poliovirus RNA: implications for internal translation initiation.
Initiation of translation on poliovirus mRNA occurs by internal binding of ribosomes to a region within the 5'-noncoding portion of the mRNA. The mechanistic details and trans-acting factors involved in this event are not understood fully. We used a mobility-shift electrophoresis assay to identify a specific RNA-protein complex, which can form between an RNA fragment that contains nucleotides 559-624 of the poliovirus 5' UTR (untranslated region) and a component or components of a HeLa cell extract. Complex formation was reduced greatly in a reticulocyte lysate or a wheat-germ extract. A 52-kD polypeptide (p52) has been identified as part of the protein-RNA complex by use of an UV cross-linking assay. This polypeptide apparently is not a known translation initiation or elongation factor. The possible involvement of p52 in translation initiation of poliovirus protein synthesis is discussed.
Meerovitch
K
K
Department of Biochemistry, McGill University, Montréal, Canada.
Pelletier
J
J
Sonenberg
N
N
D001483:Base Sequence; D003432:Cross-Linking Reagents; D007438:Introns; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010445:Peptide Elongation Factors / Q000235:genetics; D010448:Peptide Initiation Factors / Q000235:genetics* / Q000378:metabolism; D017955:Poliovirus / Q000235:genetics*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012156:Reticulocytes / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
D003432:Cross-Linking Reagents; D010445:Peptide Elongation Factors; D010448:Peptide Initiation Factors; D012333:RNA, Messenger; D012367:RNA, Viral