title: The nucleolus: structure/function relationship in RNA metabolism.
abstract: The nucleolus is the ribosome factory of the cells. This is the nuclear domain where ribosomal RNAs are synthesized, processed, and assembled with ribosomal proteins. Here we describe the classical tripartite organization of the nucleolus in mammals, reflecting ribosomal gene transcription and pre-ribosomal RNA (pre-rRNA) processing efficiency: fibrillar center, dense fibrillar component, and granular component. We review the nucleolar organization across evolution from the bipartite organization in yeast to the tripartite organization in humans. We discuss the basic principles of nucleolar assembly and nucleolar structure/function relationship in RNA metabolism. The control of nucleolar assembly is presented as well as the role of pre-existing machineries and pre-rRNAs inherited from the previous cell cycle. In addition, nucleoli carry many essential extra ribosomal functions and are closely linked to cellular homeostasis and human health. The last part of this review presents recent advances in nucleolar dysfunctions in human pathology such as cancer and virus infections that modify the nucleolar organization.
authors.affiliation: Nuclei and cell cycle, Institut Jacques Monod-UMR 7592 CNRS, Université Paris Diderot, 75205 Paris cedex 13, France. daniele.hernandez-verdun@univ-paris-diderot.fr
authors.forename: Danièle
authors.initials: D
authors.lastname: Hernandez-Verdun
authors.forename: Pascal
authors.initials: P
authors.lastname: Roussel
authors.forename: Marc
authors.initials: M
authors.lastname: Thiry
authors.forename: Valentina
authors.initials: V
authors.lastname: Sirri
authors.forename: Denis L J
authors.initials: DL
authors.lastname: Lafontaine
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D056890:Eukaryota / Q000235:genetics / Q000378:metabolism; D006801:Humans; D012313:RNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics; D004718:Saccharomycetales / Q000235:genetics / Q000648:ultrastructure; D013329:Structure-Activity Relationship; D014158:Transcription, Genetic
chemical_list: D012322:RNA Precursors; D012313:RNA