Old and new faces of the nucleolus

Abstract

The second EMBO Workshop on the Nucleolus and Disease took place between 23 and 25 June 2008, in the beautiful setting of the Marriot Breadsall Priory Hotel in Derby, UK, and was organized by J. Hiscox and D. Matthews. ![][1] See Glossary for abbreviations used in this article The second European Molecular Biology Organization workshop on the nucleolus brought together scientists from around the world to discuss the progress made in studies of the basic functions of the nucleolus, and the link between nucleolar functions and disease. Although the primary function of this prominent nuclear organelle is in ribosome biogenesis, a growing body of evidence indicates that it also participates in other aspects of RNA processing, as well as in the regulation of mitosis, cell growth and death, stress responses and the cell cycle (Fig 1). Indeed, the nucleolus has emerged as a highly complex and multifunctional regulatory compartment, the roles of which in diverse biological processes we are only just beginning to understand. Figure 1. The many functions of the nucleolus. In addition to its traditional function in ribosome production and assembly, the nucleolus has a growing repertoire of ‘non‐traditional’ functions, including: processing and maturation of tRNAs, snoRNAs and snRNAs; transport of mRNAs; assembly of a range of RNPs; replication of animal and plant viruses; sequestration of proteins that regulate the cell cycle and apoptosis; ageing; and cell stress responses and production of heterochromatic siRNAs (in plants). Supplied by J. Brown. ARF, alternate reading frame product of the cyclin‐dependent kinase inhibitor 2a gene; Cdc14, cell division cycle protein 14; HIV, human immunodeficiency virus; JNK2, Jun amino‐terminal kinase‐2; MDM2, product of the human double minute 2 gene; mRNA, messenger RNA; NFκB, nuclear factor‐κB; PP1γ, γ‐isoform of protein phosphatase 1; rDNA, ribosomal DNA; RelA, a subunit of NF‐κB, also known as p65; Rev, regulator … [1]: /embed/graphic-1.gif