Environmental cues induce a long noncoding RNA-dependent remodeling of the nucleolus

Mathieu D. Jacob, Timothy E. Audas, James Uniacke, Laura Trinkle-Mulcahy, Stephen Lee

Research output: Contribution to journalArticle

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Abstract

The nucleolus is a plurifunctional organelle in which structure and function are intimately linked. Its structural plasticity has long been appreciated, particularly in response to transcriptional inhibition and other cellular stresses, although the mechanism and physiological relevance of these phenomena are unclear. Using MCF-7 and other mammalian cell lines, we describe a structural and functional adaptation of the nucleolus, triggered by heat shock or physiological acidosis, that depends on the expression of ribosomal intergenic spacer long noncoding RNA (IGS lncRNA). At the heart of this process is the de novo formation of a large subnucleolar structure, termed the detention center (DC). The DC is a spatially and dynamically distinct region, characterized by an 8-anilino-1-naphthalenesulfonate-positive hydrophobic signature. Its formation is accompanied by redistribution of nucleolar factors and arrest in ribosomal biogenesis. Silencing of regulatory IGS lncRNA prevents the creation of this structure and allows the nucleolus to retain its tripartite organization and transcriptional activity. Signal termination causes a decrease in IGS transcript levels and a return to the active nucleolar conformation. We propose that the induction of IGS lncRNA by environmental signals operates as a molecular switch that regulates the structure and function of the nucleolus.

Original languageEnglish (US)
Pages (from-to)2943-2953
Number of pages11
JournalMolecular biology of the cell
Volume24
Issue number18
DOIs
StatePublished - Sep 15 2013

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ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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