TORC2-SGK-1 signaling integrates external signals to regulate autophagic turnover of mitochondria via mtROS

Thomas Heimbucher; Wenjing Qi; Ralf Baumeister

doi:10.1080/15548627.2020.1749368

TORC2-SGK-1 signaling integrates external signals to regulate autophagic turnover of mitochondria via mtROS

Autophagy. 2020 Jun;16(6):1154-1156. doi: 10.1080/15548627.2020.1749368. Epub 2020 Apr 15.

Authors

Thomas Heimbucher¹, Wenjing Qi^{1

2}, Ralf Baumeister^{1

2

3}

Affiliations

¹ Bioinformatics and Molecular Genetics, Faculty of Biology, University of Freiburg , Freiburg, Germany.
² Signalling Research Centres BIOSS and CIBSS, University of Freiburg , Freiburg, Germany.
³ Center for Biochemistry and Molecular Cell Research, Faculty of Medicine, University of Freiburg , Freiburg, Germany.

Abstract

Macroautophagy/autophagy is an evolutionarily conserved cellular degradation and recycling process that is tightly regulated by external stimuli, diet, and stress. Our recent findings suggest that in C. elegans, a nutrient sensing pathway mediated by MTORC2 (mechanistic target of rapamycin kinase complex 2) and its downstream effector kinase SGK-1 (serum- and glucocorticoid-inducible kinase homolog 1) suppresses autophagy, involving mitophagy. Induced autophagy/mitophagy in MTORC2-deficient animals slows down development and impairs reproduction independently of the SGK-1 effectors DAF-16/FOXO and SKN-1/NFE2L2/NRF2. In this punctum, we discuss how TORC2-SGK-1 signaling might regulate autophagic turnover and its impact on mitochondrial homeostasis via linking mitochondria-derived reactive oxygen species (mtROS) production to mitophagic turnover.

Keywords: Autophagy; MTORC (mechanistic target of rapamycin kinase complex); ROS (reactive oxygen species); SGK-1 (serum- and glucocorticoid-inducible kinase homolog 1); VDAC1 (voltage dependent anion channel 1); mitophagy.

Publication types

Research Support, Non-U.S. Gov't
Comment

MeSH terms

Animals
Autophagy
Caenorhabditis elegans Proteins*
Caenorhabditis elegans*
Mechanistic Target of Rapamycin Complex 2
Mitochondria
Protein Serine-Threonine Kinases
Reactive Oxygen Species

Substances

Caenorhabditis elegans Proteins
Reactive Oxygen Species
Mechanistic Target of Rapamycin Complex 2
Protein Serine-Threonine Kinases
Sgk-1 protein, C elegans

Grants and funding

This work was funded by grants from the German Research Foundation (DFG) (SFB746, SFB850, 7 SFB1381), the Germany's Excellence Strategy (CIBSS – EXC-2189 – Project ID 8 390939984) and the German Excellence Initiative (BIOSS - EXC 294) to R.B.