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Updated: Dec 17, 2025
In Vivo Modeling of the Morbid Human Genome using Danio rerio
Published on: August 24, 2013
A missense mutation in the MLKL brace region promotes lethal neonatal inflammation and hematopoietic dysfunction
Joanne M Hildebrand1,2, Maria Kauppi3,4, Ian J Majewski3,4
1The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia. jhildebrand@wehi.edu.au.
Abstract:
MLKL is the essential effector of necroptosis, a form of programmed lytic cell death. We have isolated a mouse strain with a single missense mutation, MlklD139V, that alters the two-helix 'brace' that connects the killer four-helix bundle and regulatory pseudokinase domains. This confers constitutive, RIPK3 independent killing activity to MLKL. Homozygous mutant mice develop lethal postnatal inflammation of the salivary glands and mediastinum. The normal embryonic development of MlklD139V homozygotes until birth, and the absence of any overt phenotype in heterozygotes provides important in vivo precedent for the capacity of cells to clear activated MLKL. These observations offer an important insight into the potential disease-modulating roles of three common human MLKL polymorphisms that encode amino acid substitutions within or adjacent to the brace region. Compound heterozygosity of these variants is found at up to 12-fold the expected frequency in patients that suffer from a pediatric autoinflammatory disease, chronic recurrent multifocal osteomyelitis (CRMO).
Insights
A mutation in MLKL (mixed lineage kinase domain-like protein) causes programmed cell death and lethal inflammation in mice. This finding suggests MLKL variants may influence human autoinflammatory diseases like CRMO.
Area of Science:
- Cellular Biology
- Immunology
- Genetics
Background:
- MLKL is the key effector protein in necroptosis, a regulated form of lytic cell death.
- Understanding MLKL's function is crucial for studying inflammatory diseases.
Purpose of the Study:
- To investigate the functional consequences of a specific MLKL mutation (MlklD139V) in vivo.
- To explore the link between MLKL variants and human autoinflammatory diseases.
Main Methods:
- Generated and analyzed a mouse strain with a MlklD139V missense mutation.
- Observed the phenotype of homozygous and heterozygous mutant mice.
- Examined the association of human MLKL polymorphisms with CRMO patient data.
Main Results:
- The MlklD139V mutation resulted in constitutive, RIPK3-independent MLKL activation and cell death.
- Homozygous mutant mice exhibited lethal postnatal inflammation in salivary glands and mediastinum.
- Human MLKL polymorphisms near the mutation site were found at higher frequencies in CRMO patients.
Conclusions:
- The MlklD139V mutation demonstrates MLKL's critical role in regulating inflammation.
- Cells can tolerate activated MLKL during embryonic development.
- Common MLKL variants may contribute to the pathogenesis of pediatric autoinflammatory diseases such as CRMO.
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