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Method for Measuring the Activity of Deubiquitinating Enzymes in Cell Lines and Tissue Samples
Published on: May 10, 2015
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The deubiquitylase USP9X controls ribosomal stalling
Anne Clancy1, Claire Heride1,2, Adán Pinto-Fernández3
1Department of Molecular Physiology and Cell Signaling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK.
The Journal of Cell Biology
|January 28, 2021
Summary
The deubiquitylase USP9X regulates the stability of essential ribosomal quality control proteins Makorin and ZNF598. Inhibiting USP9X impairs ribosome rescue pathways, impacting protein synthesis quality control.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Ribosome stalling during translation can lead to dangerous collisions between ribosomes.
- A specialized cellular machinery, involving Makorin and ZNF598 ubiquitin E3 ligases, resolves these di-ribosomal complexes through ubiquitylation.
- Understanding the regulation of this ribosomal quality control pathway is crucial for cellular health.
Purpose of the Study:
- To investigate the role of the deubiquitylase USP9X in regulating ribosomal quality control.
- To identify novel interactions and functions of USP9X within the cellular protein quality control network.
Main Methods:
- Development of a small-molecule inhibitor targeting USP9X.
- Proteomics analysis of HCT116 cells treated with the USP9X inhibitor.
- Co-immunoprecipitation assays to study protein interactions.
Main Results:
- USP9X inhibition led to decreased levels of Makorin 2 and ZNF598 ubiquitin E3 ligases.
- USP9X was found to directly interact with Makorin and ZNF598, regulating their protein stability.
- Impairment of USP9X activity diminished the efficiency of the ribosomal quality control pathway.
Conclusions:
- USP9X plays a critical role in maintaining the stability of key ubiquitin E3 ligases involved in ribosomal quality control.
- Targeting USP9X impacts the cellular response to ribosome stalling and protein synthesis errors.
- These findings highlight USP9X as a potential therapeutic target for diseases associated with protein synthesis dysfunction.
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