July 1, 1989Genes & Development271 citationsOpen Access
A cellular protein that binds to the 5'-noncoding region of poliovirus RNA: implications for internal translation initiation.
Resultado clave
A 52-kD polypeptide (p52) from HeLa cell extracts was identified as part of a specific protein-RNA complex that forms with the 5'-noncoding region of poliovirus RNA.
PICO estructurado
P
Población
HeLa cell extract, reticulocyte lysate, wheat-germ extract, and poliovirus RNA fragment (nucleotides 559-624 of 5' UTR)
I
Intervención
Mobility-shift electrophoresis assay and UV cross-linking assay
O
Resultado
Identification of specific RNA-protein complex and associated polypeptidessurrogate
Identified a 52-kD cellular protein that binds to the poliovirus 5' UTR, which may be involved in internal translation initiation.
Resumen
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.