Nature Communications (Nov 2023)

Nucleolar reorganization after cellular stress is orchestrated by SMN shuttling between nuclear compartments

  • Shaqraa Musawi,
  • Lise-Marie Donnio,
  • Zehui Zhao,
  • Charlène Magnani,
  • Phoebe Rassinoux,
  • Olivier Binda,
  • Jianbo Huang,
  • Arnaud Jacquier,
  • Laurent Coudert,
  • Patrick Lomonte,
  • Cécile Martinat,
  • Laurent Schaeffer,
  • Denis Mottet,
  • Jocelyn Côté,
  • Pierre-Olivier Mari,
  • Giuseppina Giglia-Mari

DOI
https://doi.org/10.1038/s41467-023-42390-4
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 17

Abstract

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Abstract Spinal muscular atrophy is an autosomal recessive neuromuscular disease caused by mutations in the multifunctional protein Survival of Motor Neuron, or SMN. Within the nucleus, SMN localizes to Cajal bodies, which are associated with nucleoli, nuclear organelles dedicated to the first steps of ribosome biogenesis. The highly organized structure of the nucleolus can be dynamically altered by genotoxic agents. RNAP1, Fibrillarin, and nucleolar DNA are exported to the periphery of the nucleolus after genotoxic stress and, once DNA repair is fully completed, the organization of the nucleolus is restored. We find that SMN is required for the restoration of the nucleolar structure after genotoxic stress. During DNA repair, SMN shuttles from the Cajal bodies to the nucleolus. This shuttling is important for nucleolar homeostasis and relies on the presence of Coilin and the activity of PRMT1.