ATM functions at the peroxisome to induce pexophagy in response to ROS.

Peroxisomes are highly metabolic, autonomously replicating organelles that generate reactive oxygen species (ROS) as a by-product of fatty acid β-oxidation. Consequently, cells must maintain peroxisome homeostasis, or risk pathologies associated with too few peroxisomes, such as peroxisome biogenesis disorders, or too many peroxisomes, inducing oxidative damage and promoting diseases such ...
as cancer. We report that the PEX5 peroxisome import receptor binds ataxia-telangiectasia mutated (ATM) and localizes this kinase to the peroxisome. In response to ROS, ATM signalling activates ULK1 and inhibits mTORC1 to induce autophagy. Specificity for autophagy of peroxisomes (pexophagy) is provided by ATM phosphorylation of PEX5 at Ser 141, which promotes PEX5 monoubiquitylation at Lys 209, and recognition of ubiquitylated PEX5 by the autophagy adaptor protein p62, directing the autophagosome to peroxisomes to induce pexophagy. These data reveal an important new role for ATM in metabolism as a sensor of ROS that regulates pexophagy.
Mesh Terms:
Adaptor Proteins, Signal Transducing, Animals, Ataxia Telangiectasia Mutated Proteins, Autophagy, Blotting, Western, Cells, Cultured, HEK293 Cells, Hep G2 Cells, Humans, Hydrogen Peroxide, MCF-7 Cells, Mice, Knockout, Microscopy, Electron, Microscopy, Fluorescence, Multiprotein Complexes, Mutation, Peroxisomes, Phagosomes, Phosphorylation, Protein Binding, RNA Interference, Reactive Oxygen Species, Receptors, Cytoplasmic and Nuclear, Reverse Transcriptase Polymerase Chain Reaction, Serine, TOR Serine-Threonine Kinases
Nat. Cell Biol.
Date: Oct. 01, 2015
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