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Association and dissociation between the mitochondrial Far complex and Atg32 regulate mitophagy
Aleksei Innokentev1, Kentaro Furukawa1, Tomoyuki Fukuda1
1Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
Elife
|December 15, 2020
Summary
The Far complex, including Ppg1, inhibits mitophagy by dephosphorylating Atg32. Its dissociation from Atg32 is crucial for mitophagy regulation in yeast.
Area of Science:
- Cellular Biology
- Molecular Biology
- Biochemistry
Background:
- Mitophagy is vital for maintaining mitochondrial health.
- Phosphorylation of Atg32 by casein kinase 2 is essential for yeast mitophagy.
- The STRIPAK complex, comprising Ppg1 and the Far complex, counteracts Atg32 phosphorylation, but its mechanism is unclear.
Purpose of the Study:
- To elucidate the mechanism by which the Ppg1-Far complex regulates mitophagy.
- To investigate the distinct roles of Far complex subpopulations in mitochondria and endoplasmic reticulum.
- To understand the interaction between the Far complex and the mitophagy receptor Atg32.
Main Methods:
- Subcellular localization studies to identify Far complex subpopulations.
- Biochemical assays to analyze Ppg1-Far complex integrity and Atg32 interaction.
- Genetic manipulation (artificial tethering) to assess mitophagy regulation.
Main Results:
- Two Far complex subpopulations were identified in mitochondria and ER, with distinct functions.
- The mitochondrial subpopulation inhibits mitophagy via Atg32 dephosphorylation.
- The Ppg1-Far complex preferentially binds phosphorylated Atg32, and this interaction decreases upon mitophagy induction.
Conclusions:
- Ppg1-mediated Far complex formation and its subsequent dissociation from Atg32 are critical for mitophagy control.
- Mitochondrial and ER-localized Far complexes have divergent roles in cellular signaling and mitophagy.
- Understanding this regulation provides insights into mitochondrial homeostasis.
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