EMD-50415
Subtomogram average of 80S ribosomes in S. cerevisiae under acute glucose starvation
EMD-50415
Subtomogram averaging10.2 Å
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Map released: 17/07/2024
Last modified: 14/08/2024
Sample Organism:
S.cerevisiae
Sample: Cryo-focused ion beam milled lamellae of S.cerevisiae cells under acute glucose starvation
Raw data: EMPIAR-12104
Deposition Authors: Spindler MC
,
Mahamid J
Sample: Cryo-focused ion beam milled lamellae of S.cerevisiae cells under acute glucose starvation
Raw data: EMPIAR-12104
Deposition Authors: Spindler MC
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Polysome collapse and RNA condensation fluidize the cytoplasm.
Xie Y,
Shu T
,
Liu T,
Spindler MC
,
Mahamid J
,
Hocky GM
,
Gresham D,
Holt LJ
(2024) Mol Cell , 84 , 2698 - 2716.e9
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(2024) Mol Cell , 84 , 2698 - 2716.e9
Abstract:
The cell interior is packed with macromolecules of mesoscale size, and this crowded milieu significantly influences cellular physiology. Cellular stress responses almost universally lead to inhibition of translation, resulting in polysome collapse and release of mRNA. The released mRNA molecules condense with RNA-binding proteins to form ribonucleoprotein (RNP) condensates known as processing bodies and stress granules. Here, we show that polysome collapse and condensation of RNA transiently fluidize the cytoplasm, and coarse-grained molecular dynamic simulations support this as a minimal mechanism for the observed biophysical changes. Increased mesoscale diffusivity correlates with the efficient formation of quality control bodies (Q-bodies), membraneless organelles that compartmentalize misfolded peptides during stress. Synthetic, light-induced RNA condensation also fluidizes the cytoplasm. Together, our study reveals a functional role for stress-induced translation inhibition and formation of RNP condensates in modulating the physical properties of the cytoplasm to enable efficient response of cells to stress conditions.
The cell interior is packed with macromolecules of mesoscale size, and this crowded milieu significantly influences cellular physiology. Cellular stress responses almost universally lead to inhibition of translation, resulting in polysome collapse and release of mRNA. The released mRNA molecules condense with RNA-binding proteins to form ribonucleoprotein (RNP) condensates known as processing bodies and stress granules. Here, we show that polysome collapse and condensation of RNA transiently fluidize the cytoplasm, and coarse-grained molecular dynamic simulations support this as a minimal mechanism for the observed biophysical changes. Increased mesoscale diffusivity correlates with the efficient formation of quality control bodies (Q-bodies), membraneless organelles that compartmentalize misfolded peptides during stress. Synthetic, light-induced RNA condensation also fluidizes the cytoplasm. Together, our study reveals a functional role for stress-induced translation inhibition and formation of RNP condensates in modulating the physical properties of the cytoplasm to enable efficient response of cells to stress conditions.