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ATG8ylation of proteins: A way to cope with cell stress?

Julian M Carosi1, Thanh N Nguyen2, Michael Lazarou2

  • 1Lysosomal Health in Ageing, Hopwood Centre for Neurobiology, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia.

The Journal of Cell Biology
|October 21, 2021
PubMed

Insights

The ATG8 protein family modifies cellular proteins via ATG8ylation, a process influenced by mitochondrial damage and ATG4 proteases. This suggests ATG8s are emerging as key regulators in protein modification pathways.

Area of Science:

  • Cellular Biology
  • Molecular Biology
  • Autophagy Research

Background:

  • The ATG8 family of proteins is crucial for regulating autophagy.
  • Autophagy is a fundamental cellular process for degrading and recycling damaged components.

Purpose of the Study:

  • To investigate the novel function of ATG8 proteins beyond autophagy.
  • To characterize the process of ATG8ylation and its regulatory mechanisms.

Main Methods:

  • Conjugation assays to detect ATG8ylation.
  • Mitochondrial stress induction models.
  • Protease activity assays using ATG4 proteases.

Main Results:

  • ATG8 proteins were confirmed to conjugate directly to cellular proteins, a process named ATG8ylation.
  • ATG8ylation is significantly enhanced under conditions of mitochondrial damage.
  • ATG4 proteases antagonize and reverse the ATG8ylation process.

Conclusions:

  • ATG8 proteins have an emerging role as ubiquitin-like modifiers, similar to ubiquitin.
  • ATG8ylation represents a novel post-translational modification with potential implications in cellular regulation.
  • The interplay between mitochondrial status, ATG8ylation, and ATG4 proteases highlights a new layer of cellular control.

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