Proteins and ribonucleic acids associate to form a large number of macromolecular complexes (ribonucleoprotein complexes, RNPs) in all living cells. Many of them are acting together as crucial players in numerous biological networks. Consequently, impaired RNP formation and function are linked to cellular malfunction and disease. Accordingly, analyses of dynamic RNP-assembly processes and the regulation of RNP function have been central topics in basic research.Formation and function of RNPs depend on the interplay of many RNA-producing or RNA-containing protein complexes. First, the regulated synthesis of the RNA component is critical for RNP formation and significantly influences RNA-maturation steps in space and time. Second, a functional network of many RNA-binding, RNA-modifying and RNA-folding complexes participates to mature emerging RNPs. Third, the interplay of different RNPs is essential for RNP activity, as exemplified by the regulation of ribosome activity, by microRNA-containing protein complexes (miRNPs), or regulation of transcription by long non-coding RNA (lncRNA) containing complexes. Investigation of processes leading to mature ribosomes served as a trailhead to understand principles of RNP biogenesis. Subsequently, projects dealing with ribosome function and formation of non-ribosomal RNPs were integrated during the first two funding periods, expanding the scope of the CRC. For the third funding period, particular emphasis is laid on understanding molecular mechanisms of assembly events of both maturating ribosomes and non-ribosomal RNPs and control of their function. This is reflected in the new title of the CRC960 “RNP biogenesis: assembly of ribosomes and non-ribosomal RNPs and control of their function”. This assures that the central focus of the CRC 960 – RNP biogenesis - remains the same, while non-ribosomal RNPs are now explicitly included. In summary, our combined efforts will further the understanding of common principles, specific features and mechanisms of RNP assembly. Several high-resolution structures of RNPs related to the topic of this CRC became available during the last funding period. Structures like those of eukaryotic pre-ribosomal particles, RNA polymerase I initiation- and elongation-complexes, and miRNA containing RNPs have a major impact on the progress of several ongoing CRC-projects. The option to determine high-resolution structures of RNPs on-site and to synergistically combine these structural studies with biophysical, biochemical and cell biological approaches lays an excellent basis for our research that aims to understand and explore the structure-function relationships as well as mechanisms and dynamics in RNP biology.
