Nucleoporin foci are stress-sensitive condensates dispensable for C. elegans nuclear pore assembly

Laura Thomas, Basma Taleb Ismail, Peter Askjaer, Geraldine Seydoux

Research output: Contribution to journalArticlepeer-review

Abstract

Nucleoporins (Nups) assemble nuclear pores that form the permeability barrier between nucleoplasm and cytoplasm. Nucleoporins also localize in cytoplasmic foci proposed to function as pore pre-assembly intermediates. Here, we characterize the composition and incidence of cytoplasmic Nup foci in an intact animal, C. elegans. We find that, in young non-stressed animals, Nup foci only appear in developing sperm, oocytes and embryos, tissues that express high levels of nucleoporins. The foci are condensates of highly cohesive FG repeat-containing nucleoporins (FG-Nups), which are maintained near their solubility limit in the cytoplasm by posttranslational modifications and chaperone activity. Only a minor fraction of FG-Nup molecules concentrate in Nup foci, which dissolve during M phase and are dispensable for nuclear pore assembly. Nucleoporin condensation is enhanced by stress and advancing age, and overexpression of a single FG-Nup in post-mitotic neurons is sufficient to induce ectopic condensation and organismal paralysis. We speculate that Nup foci are non-essential and potentially toxic condensates whose assembly is actively suppressed in healthy cells.

Original languageEnglish (US)
Article numbere112987
JournalEMBO Journal
Volume42
Issue number13
DOIs
StatePublished - Jul 3 2023

Keywords

  • C. elegans
  • aging
  • condensate
  • nucleoporin
  • oocyte

ASJC Scopus subject areas

  • General Biochemistry, Genetics and Molecular Biology
  • General Immunology and Microbiology
  • Molecular Biology
  • General Neuroscience

Fingerprint

Dive into the research topics of 'Nucleoporin foci are stress-sensitive condensates dispensable for C. elegans nuclear pore assembly'. Together they form a unique fingerprint.

Cite this