Initiation of protein synthesis by the eukaryotic translational apparatus on circular RNAs.
The ribosome scanning model predicts that eukaryotic ribosomal 40S subunits enter all messenger RNAs at their 5' ends. Here, it is reported that eukaryotic ribosomes can initiate translation on circular RNAs, but only if the RNAs contain internal ribosome entry site elements. Long-repeating polypeptide chains were synthesized from RNA circles with continuous open reading frames. These results indicate that ribosomes can translate such RNA circles for multiple consecutive rounds and that the free 5' end of a messenger RNA is not necessarily the entry point for 40S subunits.
Chen
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CY
Department of Biochemistry, Biophysics and Genetics, Dyde Laboratory, University of Colorado Health Sciences Center, Denver 80262, USA.
Sarnow
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P
D003062:Codon; D004686:Encephalomyocarditis virus / Q000235:genetics; D016366:Open Reading Frames; D010442:Peptide Chain Initiation, Translational; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D000079962:RNA, Circular; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D013698:Templates, Genetic
D003062:Codon; D000079962:RNA, Circular; D012333:RNA, Messenger; D012313:RNA