To be or not to be in the nucleolus.
Compartmentalization has long been known to have a key role in regulation of cellular processes. By keeping enzymes and regulatory complexes in compartments where the delivery of substrate or exit of product is controlled, competing reactions can occur simultaneously in different parts of the cell. Moreover, spatial confinement facilitates the working of molecules participating in reaction chains and is crucial for coupling unfavourable with energetically favourable chemical reactions. Although in many cases intracellular compartmentalization relies on boundaries imposed by membranes, several non-membrane-bounded compartments exist in eukaryotic cells. One of these, the nucleolus, has recently attracted much attention. The emerging view is that molecular confinement in the nucleolus actively contributes to the control of cellular survival and proliferation.
Carmo-Fonseca
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M
Institute of Histology and Embryology, Faculty of Medicine, University of Lisbon, Av. Prof. Egas Moniz 1649-028 Lisbon, Portugal. carmo.fonseca@fm.ul.pt
Mendes-Soares
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L
Campos
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I
D000818:Animals; D001692:Biological Transport; D002451:Cell Compartmentation; D002453:Cell Cycle; D002466:Cell Nucleolus / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D012320:RNA Polymerase III / Q000378:metabolism; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
D002843:Chromatin; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D012097:Repressor Proteins; D012320:RNA Polymerase III