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Updated: Oct 15, 2025

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis
08:55

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis

Published on: August 7, 2018

11.0K

Oligomerization-driven MLKL ubiquitylation antagonizes necroptosis

Zikou Liu1,2, Laura F Dagley1,2, Kristy Shield-Artin1,2

  • 1The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.

The EMBO Journal
|October 26, 2021
PubMed

Insights

Ubiquitylation of Mixed lineage kinase domain-like (MLKL) occurs after its activation during necroptosis. This ubiquitylation regulates MLKL turnover and prevents spontaneous cell death.

Area of Science:

  • Cellular biology
  • Molecular mechanisms of cell death
  • Programmed cell death pathways

Background:

  • Mixed lineage kinase domain-like (MLKL) is the effector protein in necroptosis, a programmed cell death pathway.
  • Receptor-interacting serine/threonine protein kinase 3 (RIPK3) activates MLKL, leading to membrane disruption.
  • The role and mechanism of MLKL ubiquitylation during necroptosis remain unclear.

Purpose of the Study:

  • To elucidate the mechanism and significance of MLKL ubiquitylation in necroptosis.
  • To investigate the regulation of MLKL activity by ubiquitylation.
  • To understand how ubiquitylation controls basal MLKL levels and prevents unwanted cell death.

Main Methods:

  • Analysis of MLKL ubiquitylation in response to necroptotic stimuli.
  • Cellular fractionation to localize ubiquitylated MLKL.
  • Expression of deubiquitylating enzymes to assess ubiquitylation's impact.
  • Site-directed mutagenesis to identify ubiquitylation sites on MLKL.
  • MLKL-deubiquitylating enzyme (DUB) fusion strategy to study constitutive deubiquitylation.

Main Results:

  • Necroptosis-specific multi-mono-ubiquitylation of MLKL occurs post-activation and oligomerization.
  • Ubiquitylated MLKL localizes to membranes and protein aggregates.
  • MLKL ubiquitylation occurs on at least four lysine residues and targets MLKL for proteasomal and lysosomal degradation.
  • Constitutive deubiquitylation of MLKL leads to its auto-activation, independent of necroptosis signaling.

Conclusions:

  • Ubiquitylation of MLKL is a crucial regulatory event in necroptosis.
  • Ubiquitylation controls the turnover of activated MLKL and prevents spontaneous necroptosis.
  • This study reveals a dual role for ubiquitylation in regulating necroptosis kinetics and basal cell death prevention.
Keywords:
DUB-fusionMLKLmembranesnecroptosisubiquitylation

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