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Updated: Jan 2, 2026
In Vitro Ubiquitination and Deubiquitination Assays of Nucleosomal Histones
Published on: July 25, 2019
Post-translational Modification of OTULIN Regulates Ubiquitin Dynamics and Cell Death
1Department of Microbiology and Immunology, McGill University, Montréal, QC H3G 0B1, Canada.
Abstract:
Linear ubiquitination has emerged as an important post-translational modification that regulates NF-κB activation, inflammation, and cell death in both immune and non-immune compartments, including the skin. The deubiquitinase OTULIN specifically disassembles linear ubiquitin chains generated by the linear ubiquitin assembly complex (LUBAC) and is necessary to prevent embryonic lethality and autoinflammatory disease. Here, we dissect the direct role of OTULIN in cell death and find that OTULIN limits apoptosis and necroptosis in keratinocytes. During apoptosis, OTULIN is cleaved by capase-3 at Asp-31 into a C-terminal fragment that restricts caspase activation and cell death. During necroptosis, OTULIN is hyper-phosphorylated at Tyr-56, which modulates RIPK1 ubiquitin dynamics and promotes cell death. OTULIN Tyr-56 phosphorylation is counteracted by the activity of dual-specificity phosphatase 14 (DUSP14), which we identify as an OTULIN phosphatase that limits necroptosis. Our data provide evidence of dynamic post-translational modifications of OTULIN and highlight their importance in cell death outcome.
Insights
OTULIN limits skin cell death by undergoing specific modifications. Cleavage during apoptosis and phosphorylation during necroptosis control cell death pathways, with DUSP14 counteracting necroptosis.
Area of Science:
- Molecular Biology
- Immunology
- Dermatology
Background:
- Linear ubiquitination is a key post-translational modification regulating inflammation and cell death.
- OTULIN, a deubiquitinase, removes linear ubiquitin chains and is vital for preventing lethality and autoinflammatory diseases.
Purpose of the Study:
- To investigate the direct role of OTULIN in regulating apoptosis and necroptosis in keratinocytes.
- To identify the post-translational modifications of OTULIN that influence cell death outcomes.
Main Methods:
- Analysis of OTULIN cleavage by caspase-3 during apoptosis.
- Investigation of OTULIN phosphorylation at Tyr-56 during necroptosis.
- Identification and functional characterization of DUSP14 as an OTULIN phosphatase.
Main Results:
- OTULIN cleavage by caspase-3 at Asp-31 limits apoptosis by restricting caspase activation.
- OTULIN hyper-phosphorylation at Tyr-56 promotes necroptosis by modulating RIPK1 ubiquitination.
- DUSP14 dephosphorylates OTULIN at Tyr-56, thereby limiting necroptosis.
Conclusions:
- Dynamic post-translational modifications of OTULIN are critical regulators of keratinocyte apoptosis and necroptosis.
- OTULIN's dual regulatory mechanisms (cleavage and phosphorylation) fine-tune cell death pathways.
- DUSP14 acts as a crucial counter-regulator of OTULIN-mediated necroptosis.
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