The genome of every eukaryotic cell is packaged within the cell nucleus. Conceptually, the role of the nucleus is to provide an environment suitable for both expression and maintenance of the genome. These two functions can be sub‐divided into a broad range of activities, including such diverse processes as transcription, RNA processing and export, DNA replication and DNA damage sensing and repair. In addition the genome must be tightly packaged, yet large parts of it nonetheless must be readily available as a transcriptional substrate either for basal metabolism or in response to specific stimuli.
The subdivision of biological processes into spatially and/or temporally discrete compartments confers numerous advantages. It permits the segregation of otherwise mutually exclusive processes, creates locally high concentrations of factors necessary for specific events/pathways and allows the coupling of energetically favourable and unfavourable reactions. Thus...