University of Bonn develops advanced toolbox for IRES characterization

Researchers at the University of Bonn have made significant progress in understanding how ribosomes regulate gene expression. Ribosomes are essential for converting genetic information into proteins through a process called translation. This research focuses on how ribosomes interact with messenger RNA (mRNA). The team, led by Prof. Kathrin Leppek, is particularly interested in internal ribosomal entry sites (IRESes). IRESes are special sequences in RNA that help viruses like hepatitis C and poliovirus hijack host ribosomes to produce viral proteins. Unlike standard mRNA, which relies on a protective cap for translation, IRES allows for translation to start without this cap. While IRESes were first identified in viruses, recent discoveries show they also exist in the mRNAs of eukaryotic cells, which have a nucleus. This highlights their potential role in cellular translation regulation. However, accurately characterizing these IRESes has been challenging due to technical limitations. To overcome these obstacles, the Bonn researchers developed a set of new techniques for robustly testing IRES activity. One method uses circular RNA reporters to confirm IRES function. Other techniques include measuring the translation rates of specific mRNAs in mouse embryo tissues. This comprehensive approach represents a new standard for studying IRESes in laboratory settings. The findings could also have implications for synthetic biology and mRNA therapies. The research was supported by the German Research Foundation and the University of Bonn.