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Updated: Jan 16, 2026

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Measurement of mRNA Decay Rates in Saccharomyces cerevisiae Using rpb1-1 Strains
Published on: December 13, 2014
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Evaluating single-cell variability in proteasomal decay within Saccharomyces cerevisiae
Sukanya Das1, Abhyudai Singh2, Premal Shah1
1Department of Genetics, Rutgers University, Piscataway, New Jersey.
Biophysical Journal
|October 1, 2025
Summary
Protein decay rates vary significantly between individual cells, contributing to gene expression noise. Understanding this variability is crucial for accurate models of cellular processes.
Area of Science:
- Cell Biology
- Molecular Biology
- Systems Biology
Background:
- Gene expression exhibits inherent stochasticity, leading to cell-to-cell variability in protein and mRNA levels.
- This variability, known as gene expression noise, is often attributed to transcription and translation, with protein decay largely overlooked.
Purpose of the Study:
- To quantify single-cell protein decay rates for degron GFPs in Saccharomyces cerevisiae.
- To investigate cellular factors contributing to variability in protein decay kinetics.
- To highlight the significance of protein decay in stochastic gene expression models.
Main Methods:
- Utilized time-lapse microscopy to measure single-cell protein decay rates.
- Employed degron GFPs as reporters for protein stability.
- Analyzed correlations between cellular features and protein half-lives.
Main Results:
- Demonstrated substantial cell-to-cell variability in protein decay rates.
- Found that the abundance of the 20S proteasome catalytic subunit only marginally explains decay rate variability.
- Identified protein decay as a significant stochastic contributor to gene expression noise.
Conclusions:
- Protein decay rates are highly variable at the single-cell level.
- Stochastic protein decay dynamics must be incorporated into models of gene expression noise.
- Further investigation into alternative mechanisms driving decay variability is warranted.

