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Updated: Sep 28, 2025
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Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
Published on: May 10, 2022
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K27-linked ubiquitylation promotes p97 substrate processing and is essential for cell proliferation
Robert F Shearer1, Dimitris Typas1, Fabian Coscia2
1Protein Signaling Program, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark.
The EMBO Journal
|March 29, 2022
Summary
Lysine 27 (K27)-linked ubiquitylation is crucial for human cell proliferation and nuclear protein processing. This study reveals K27 ubiquitin chains
Area of Science:
- Cellular Biology
- Molecular Biology
- Ubiquitin Signaling
Background:
- Ubiquitin (Ub) conjugation regulates diverse cellular processes through various polymer linkages.
- The functional roles of atypical poly-ubiquitin topologies, like lysine 27 (K27)-linked chains, are not well understood due to limited detection tools.
Purpose of the Study:
- To investigate the specific roles of K27-linked ubiquitylation in cellular processes.
- To develop tools for the selective manipulation of K27-linked ubiquitylation.
Main Methods:
- Utilized a cell-based ubiquitin replacement strategy for conditional abrogation of K27-linked ubiquitylation.
- Investigated the impact of K27 linkage ablation on nuclear ubiquitylation dynamics and cell cycle progression.
- Examined the interaction between K27-linked ubiquitylation and the ATPase p97/VCP pathway using a model substrate (Ub(G76V)-GFP).
Main Results:
- K27-linked ubiquitylation is essential for human cell proliferation.
- Ablation of K27-linked ubiquitylation deregulates nuclear ubiquitylation and impairs cell cycle progression, acting epistatically with p97/VCP inactivation.
- K27-linked ubiquitylation directly modifies a p97-proteasome pathway substrate, and its disruption impedes substrate turnover at the p97 functional level.
Conclusions:
- K27-linked ubiquitylation plays a critical role in maintaining cell fitness.
- This ubiquitin linkage facilitates the p97-dependent processing of ubiquitylated nuclear proteins.
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