Free mRNA in excess upon polysome dissociation is a scaffold for protein multimerization to form stress granules.
Bottom Line: We further demonstrate that the delivery of single strand polynucleotides, mRNA and ssDNA, to the cytoplasm can trigger stress granule assembly.Interestingly, we also discovered that enucleated cells do form stress granules, demonstrating that the translocation to the cytoplasm of nuclear prion-like RNA-binding proteins like TIA-1 is dispensable for stress granule assembly.Within the frame of this model, the shuttling of nuclear mRNA-stabilizing proteins to the cytoplasm could dissociate stress granules or prevent their assembly.
Affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM), UMR829; Université Evry-Val d'Essonne, Evry 91025, France.Show MeSH
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Mentions: Mapping of the 15N:14N ratio showed an uniform distribution over a 9 μm2 area and statistical analysis of this ratio indicates that the RNA sample has a significant higher 15N content (15N:14N ratio = 3.96 ± 0.04%) compared to the cytoplasm of NRK cells exposed to 15N-uridine (15N:14N ratio = 0.79 ± 0.23%), see Figure 1E. This result thus indicates that 15N-uridine has been significantly incorporated to cellular RNA which is necessary to keep a high signal-to-noise ratio in the 15N:14N cartography.
Affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM), UMR829; Université Evry-Val d'Essonne, Evry 91025, France.