title: Reevaluation of the conclusion that IRES-activity reported within the 5' leader of the TIF4631 gene is due to promoter activity.
abstract: We previously reported that the 5' leader of the mRNA-encoding initiation factor eIF4G in Saccharomyces cerevisiae can function as a translational enhancer and as an internal ribosome entry site (IRES) when tested in cells. However, Verge and colleagues recently suggested that this sequence does not facilitate translation initiation, but inhibits translation in vitro and has promoter activity when tested in cells. We disagree with these conclusions and respond by showing that the data are most consistent with an internal initiation mechanism.
authors.affiliation: Department of Neurobiology, The Scripps Research Institute, and The Skaggs Institute for Chemical Biology, La Jolla, California 92037, USA. vmauro@scripps.edu
authors.forename: Vincent P
authors.initials: VP
authors.lastname: Mauro
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Edelman
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
mesh_terms: D020121:5' Untranslated Regions; D039562:Eukaryotic Initiation Factor-4F; D039603:Eukaryotic Initiation Factor-4G; D005800:Genes, Fungal; D010448:Peptide Initiation Factors / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012331:RNA, Fungal / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*; D024363:Transcription Initiation Site
chemical_list: D020121:5' Untranslated Regions; D039562:Eukaryotic Initiation Factor-4F; D039603:Eukaryotic Initiation Factor-4G; D010448:Peptide Initiation Factors; D012331:RNA, Fungal; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C107740:TIF4631 protein, S cerevisiae