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Yeast Nst1 is a novel component of P-bodies and is a specific suppressor of proteasome base assembly defects
- Source :
- Molecular Biology of the Cell
- Publication Year :
- 2021
- Publisher :
- American Society for Cell Biology (ASCB), 2021.
-
Abstract
- Proteasome assembly utilizes multiple dedicated assembly chaperones and is regulated by signaling pathways that respond to diverse stress conditions. To discover new factors influencing proteasome base assembly, we screened a tiled high-copy yeast genomic library to identify dosage suppressors of a temperature-sensitive proteasome regulatory particle (RP) base mutant. The screen identified negative salt tolerance 1 (Nst1), a protein that when overexpressed specifically suppressed the temperature sensitivity and proteasome-assembly defects of multiple base mutants. Nst1 overexpression reduced cytosolic RP ATPase (Rpt) aggregates in nas6Δ rpn14Δ cells, which lack two RP assembly chaperones. Nst1 is highly polar and predicted to have numerous intrinsically disordered regions, characteristics commonly found in proteins that can segregate into membraneless condensates. In agreement with this, both endogenous and overexpressed Nst1 could form cytosolic puncta that colocalized with processing body (P-body) components. Consistent with the accumulation of translationally inactive mRNAs in P-bodies, Nst1 overexpression inhibited global protein translation in nas6Δ rpn14Δ cells. Translational inhibition is known to suppress aggregation and proteasome assembly defects in base mutants under heat stress. Our data indicate that Nst1 is a previously overlooked P-body component that, when expressed at elevated levels inhibits translation, prevents Rpt subunit aggregation and rescues proteasome assembly under stress conditions.
- Subjects :
- Adenosine Triphosphatases
Proteomics
Proteasome Endopeptidase Complex
Saccharomyces cerevisiae Proteins
Protein subunit
Mutant
Translation (biology)
Articles
Saccharomyces cerevisiae
Salt Tolerance
Cell Biology
Processing Bodies
Biology
Cell biology
Cytosol
Proteasome
Yeasts
Proteasome assembly
P-bodies
Molecular Biology
Proteasome regulatory particle
Molecular Chaperones
Protein Binding
Subjects
Details
- ISSN :
- 19394586 and 10591524
- Volume :
- 32
- Database :
- OpenAIRE
- Journal :
- Molecular Biology of the Cell
- Accession number :
- edsair.doi.dedup.....82fe374d14f7a7edfb37929728826627