A proteomic survey of widespread protein aggregation in yeast.
Many normally cytosolic yeast proteins form insoluble intracellular bodies in response to nutrient depletion, suggesting the potential for widespread protein aggregation in stressed cells. Nearly 200 such bodies have been found in yeast by screening libraries of fluorescently tagged proteins. In order to more broadly characterize the formation of these bodies in response to stress, we employed a proteome-wide shotgun mass spectrometry assay in order to measure shifts in the intracellular solubilities of endogenous proteins following heat stress. As quantified by mass spectrometry, heat stress tended to shift the same proteins into insoluble form as did nutrient depletion; many of these proteins were also known to form foci in response to arsenic stress. Affinity purification of several foci-forming proteins showed enrichment for co-purifying chaperones, including Hsp90 chaperones. Tests of induction conditions and co-localization of metabolic enzymes participating in the same metabolic pathways suggested those foci did not correspond to multi-enzyme organizing centers. Thus, in yeast, the formation of stress bodies appears common across diverse, normally diffuse cytoplasmic proteins and is induced by multiple types of cell stress, including thermal, chemical, and nutrient stress.
Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.|Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, United States of America.
Jeremy D
JD
O'Connell
Department of Chemistry, Cambridge University, Lensfield Road, Cambridge, UK.
Mark
M
Tsechansky
Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.
Ariel
A
Royal
Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.
Daniel R
DR
Boutz
Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.|Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, United States of America.
Andrew D
AD
Ellington
Center for Systems and Synthetic Biology, Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas, United States of America.|Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, United States of America.
Edward M
EM
Marcotte
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001151:Arsenic / Q000494:pharmacology; D060746:Endoplasmic Reticulum-Associated Degradation; D005974:Glutamate-Ammonia Ligase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry*; D018869:Heat-Shock Response; D018832:Molecular Chaperones / Q000378:metabolism; D010736:Phosphoglycerate Mutase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017510:Protein Folding; D040901:Proteomics; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012995:Solubility
D018840:HSP70 Heat-Shock Proteins; C074510:HSP82 protein, S cerevisiae; D018841:HSP90 Heat-Shock Proteins; D018832:Molecular Chaperones; C090869:SSA3 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D000251:Adenosine Triphosphatases; C095973:SSA1 protein, S cerevisiae; D010736:Phosphoglycerate Mutase; C081173:glutamine synthetase I; D005974:Glutamate-Ammonia Ligase; D001151:Arsenic