The Grand Challenge of Characterizing Ribonucleoprotein Networks

Protein–RNA interactions are at the heart of cell regulation. From transcription, processing, storage, and translation, all the stages in the life cycle of an RNA depend on interactions with proteins. Although technologies are making remarkable progress in unraveling the landscape of protein–RNA interactions, many key issues are unclear.We still have to identify howmany proteins have RNA-binding ability, what are their targets and functional pathways.Moreover, while we know the number of protein-coding genes in the human genome, functional non-coding RNAs are still poorly defined. What is the function of the non-coding part of the eukaryotic transcriptome? A clear understanding of the biological functions of coding and non-coding transcripts would provide novel insights in molecular biology. What are the protein components binding to an RNA while it is being produced? Our lack of understanding of how ribonucleoprotein complexes assemble is a major rate-limiting factor to future progress in the field. We need to generate an in-depth characterization of protein–RNA complexes that form in cells during development and in response to external stimuli.