The processing of RNA and the assembly of RNA-protein complexes (RNPs) are among the most important pathways in all organisms. Their key significance is underlined by the observation that a disproportionate fraction of yeast genes involved in these processes are essential for viability and highly conserved from yeast to humans. Eukaryotic pathways of RNP maturation are quite surprisingly complex when analysed in detail, and all are monitored by RNA surveillance activities. 

Two basic questions emerge from studies of many RNP assembly and RNA processing pathways: Why are they so complicated and, given this complexity, how are “defective” particles distinguished from “normal” intermediates and selectively targeted for degradation? We are addressing these questions using a combination of biochemistry, cell biology, mathematical modeling and genetics, for which budding yeast is a particularly suitable system.