The aim of our group is to understand the role of RNA modifications in various model systems. We believe that chemical RNA modifications are responsible for the majority of distinct RNA functions. Even though there are currently more than 170 RNA modifications known, the role of the majority of them remains unknown. The 5’ termini of RNA are critical structures and are the least characterized among the RNA modifications. Until recently, only canonical structures, NAD, and CoA were recognized as 5’ RNA caps, but we have discovered an entirely new class of 5’RNA caps – dinucleoside polyphosphates (NpnN) in bacteria. The role of free NpnNs, identified fifty years ago in all types of cells, is yet to be elucidated. The cellular concentration of NpnNs increases under stress conditions. We presume that their cellular effects are mediated by RNA, where they serve as RNA caps. Therefore, we study biosynthesis, biodegradation, and the role of these noncanonical caps using modern molecular biological techniques in combination with RNA-seq methods and LC-MS.
In addition to bacterial and mammalian RNA, we also study viral RNA. We propose that viruses are perfect model systems in which to search for new eukaryotic RNA modifications, as they have a simple intrinsic organization and are amplified in infected cells. We focus on clinically relevant viral strains (e.g. HIV, picornaviruses, and vaccinia virus) as well as on the methylation profiling of viral RNA. We are also developing new capturing techniques for known RNA modifications of viral or bacterial RNAs.