Proteasome storage granules are transiently associated with the insoluble protein deposit in Saccharomyces cerevisiae

J Cell Sci. 2016 Mar 15;129(6):1190-7. doi: 10.1242/jcs.179648. Epub 2016 Jan 29.


Proteasome storage granules (PSGs) are created in yeast as part of an extensive and programmed reorganization of proteins into reversible assemblies upon carbon source depletion. Here, we demonstrate that cells distinguish dysfunctional proteasomes from PSGs on the cytosolic insoluble protein deposit (IPOD). Furthermore, we provide evidence that this is a general mechanism for the reorganization of additional proteins into reversible assemblies. Our study expands the roles of the IPOD, which might serve not only as the specific depository for amyloidogenic and misfolded proteins, but also as a potential hub from which proteins are directed to distinct cellular compartments. These findings therefore provide a framework for understanding how cells discriminate between intact and abnormal proteins under stress conditions to ensure that only structurally 'correct' proteins are deployed.

Keywords: IPOD; Insoluble protein deposit; PSGs; Proteasome; Proteasome storage granules; Protein quality control; Saccharomyces cerevisiae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytosol / metabolism
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*


  • Heat-Shock Proteins
  • Saccharomyces cerevisiae Proteins
  • Proteasome Endopeptidase Complex