The RNA infrastructure: dark matter of the eukaryotic cell?

Eukaryotes express many functional non-protein-coding RNAs (ncRNAs) that participate in the processing and regulation of other RNA molecules. By focusing on connections between RNA-based processes, common patterns emerge that form a network-like RNA infrastructure. Owing to the intracellular movement of RNA during its processing (both between nuclear compartments and between the nucleus and cytoplasm), the RNA infrastructure contains both spatial and temporal connections. As research moves away from being protein-centric and focuses more on genomics, it is timely to explore these often 'hidden' aspects of the eukaryotic cell. The general and ancestral nature of most basic RNA-processing steps places a new focus on the generality of the spatial and temporal steps in RNA processing.