Promiscuous interactions and protein disaggregases determine the material state of stress-inducible RNP granules

Elife. 2015 Aug 4;4:e06807. doi: 10.7554/eLife.06807.

Abstract

RNA-protein (RNP) granules have been proposed to assemble by forming solid RNA/protein aggregates or through phase separation into a liquid RNA/protein phase. Which model describes RNP granules in living cells is still unclear. In this study, we analyze P bodies in budding yeast and find that they have liquid-like properties. Surprisingly, yeast stress granules adopt a different material state, which is reminiscent of solid protein aggregates and controlled by protein disaggregases. By using an assay to ectopically nucleate RNP granules, we further establish that RNP granule formation does not depend on amyloid-like aggregation but rather involves many promiscuous interactions. Finally, we show that stress granules have different properties in mammalian cells, where they show liquid-like behavior. Thus, we propose that the material state of RNP granules is flexible and that the solid state of yeast stress granules is an adaptation to extreme environments, made possible by the presence of a powerful disaggregation machine.

Keywords: P body; S. cerevisiae; biochemistry; cell biology; chaperones; human; phase separation; prion-like protein; protein aggregation; stress granule.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytoplasmic Granules / metabolism*
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Multimerization*
  • Ribonucleoproteins / metabolism*
  • Saccharomycetales / metabolism*
  • Saccharomycetales / physiology
  • Stress, Physiological

Substances

  • Ribonucleoproteins

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.