In an article appearing in this week's PNAS Early Edition, an international team led by investigators at the University of British Columbia reports using mutagenesis and mass spectrometry techniques to find that, "besides directing ORF2 translation, the Israeli acute paralysis dicistrovirus IRES also directs ORFx translation." The team shows that the latter form "is mediated by a U-G base pair adjacent to the P-site tRNA-mimicking domain." The team also detected an ORFx peptide in virus-infected honey bees.
Elsewhere, using yeast complementation assays and an in planta application of lovastatin, researchers in France and Switzerland show that "defects in HMG1 catalytic activity are sufficient to inhibit miRNA activity." Moreover, the team says its results "suggest a possible basis for the requirement of isoprenoid biosynthesis for the activity of plant miRNAs, and unravel mechanistic features shared with their metazoan counterparts."