INTERNAL RIBOSOME ENTRY SITE OF ENCEPHALOMYOCARDITIS VIRUS-RNA IS UNABLE TO DIRECT TRANSLATION IN SACCHAROMYCES-CEREVISIAE

To evaluate the potential of the encephalomyocarditis virus (EMCV) int ernal ribosome entry site ORES) to promote efficient expression of for eign genes in the yeast, S. cerevisiae, we have constructed E. coli-ye ast shuttle Vectors in which the EMCV 5' non-coding region was fused t o the reporter gene, human prothymosin alpha. Efficiency of translatio n of corresponding RNA transcripts in mammalian cell-free systems was highly dependent on the sequence context and/or position of the initia tion codon. No translation of these IRES-dependent mRNAs occurred in S . cerevisiae.