Skip to Content
Merck
  • Acute Heat Stress Leads to Reversible Aggregation of Nuclear Proteins into Nucleolar Rings in Fission Yeast.

Acute Heat Stress Leads to Reversible Aggregation of Nuclear Proteins into Nucleolar Rings in Fission Yeast.

Cell reports (2020-11-12)
Paola Gallardo, Paula Real-Calderón, Ignacio Flor-Parra, Silvia Salas-Pino, Rafael R Daga
ABSTRACT

Upon acute heat stress (HS), overall mRNA transcription, processing, and export are inhibited, leading to cell growth arrest. However, how cells turn off mRNA metabolism is not fully understood. Here, we show that acute HS results in the segregation and aggregation of multiple nuclear and nucleolar proteins into ring-like structures located at the nucleolar periphery (nucleolar rings [NuRs]). NuRs sequester essential factors required for nuclear mRNA metabolism and nuclear pore complex function, as well as cell-cycle regulators. When cells are switched back to growing temperatures, NuRs disaggregate, and their components relocate to their functional environments in an Hsf1- and Hsp104-dependent manner, and concomitantly with the reinitiation of cell growth. These findings highlight the contribution of reversible protein aggregation to the inhibition of overall RNA-related activities in the nucleus and its functional relevance in the maintenance of cellular homeostasis during acute HS.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Paraformaldehyde, powder, 95%
Sigma-Aldrich
Deoxyribonucleic acid from herring sperm, single-stranded for hybridization
Glass beads, unwashed, 425-600 μm (30-40 U.S. sieve)
Sigma-Aldrich
Ribonucleoside vanadyl complexes, 200 mM
Supelco
Bicinchoninic Acid solution
Sigma-Aldrich
Cycloheximide, from microbial, ≥94% (TLC)
Sigma-Aldrich
Poly-L-lysine solution, 0.1 % (w/v) in H2O
Sigma-Aldrich
Lithium acetate, 99.95% trace metals basis
Sigma-Aldrich
Lithium acetate dihydrate, BioUltra, ≥99.0% (anhydrous)
Sigma-Aldrich
Sodium borohydride, ReagentPlus®, 99%
Sigma-Aldrich
Lectin from Glycine max (soybean), lyophilized powder, salt, essentially free
Sigma-Aldrich
Triton X-100, laboratory grade
Sigma-Aldrich
Anti-Mouse IgG (whole molecule)−Alkaline Phosphatase antibody produced in goat, affinity isolated antibody, buffered aqueous glycerol solution
Sigma-Aldrich
Triton X-100, for molecular biology
Sigma-Aldrich
Dimethyl sulfoxide, anhydrous, ≥99.9%
Nalgene® centrifuge bottles, style 3120, nominal capacity 1000 mL
Roche
Anti-GFP, from mouse IgG1κ (clones 7.1 and 13.1)