Dataset Information

MTORC2-NDRG1-Cdc42 axis couples fasting to mitochondrial fission

ABSTRACT: Fasting triggers diverse physiological adaptations including increases in circulating fatty acids and mitochondrial respiration to facilitate organismal survival. The mechanisms driving mitochondrial adaptations and respiratory sufficiency during fasting remain incompletely understood. Here we show that fasting or lipid availability stimulates mTORC2 activity. Activation of mTORC2 and phosphorylation of its downstream target NDRG1 at Ser336 sustains mitochondrial fission and respiratory sufficiency. Timelapse imaging shows that NDRG1, but not phosphorylation-deficient NDRG1Ser336Ala mutant, engages with mitochondria to facilitate fission in both control and Drp1-deficient cells, reflecting independency from Drp1. Using proteomics, an siRNA screen, and epistasis experiments, we show that mTORC2-phosphorylated NDRG1 cooperates with small GTPase Cdc42 and effectors and regulators of Cdc42 to orchestrate fission. Accordingly, RictorKO, NDRG1Ser336Ala mutants, and Cdc42-deficient cells each display mitochondrial phenotypes reminiscent of fission failure. During nutrient surplus, mTOR complexes perform anabolic functions; however, paradoxical reactivation of mTORC2 during fasting unexpectedly drives mitochondrial fission and respiration.

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Liver

SUBMITTER: Simone Sidoli

LAB HEAD: Simone Sidoli

PROVIDER: PXD041696 | Pride | 2023-04-27

REPOSITORIES: Pride

ACCESS DATA

Similar Datasets

Project description:Purpose:to verify Drp1-mediated biological pathways under physiological and ischemia conditions.Methods:C57BL/6 mice and Drp1 knockdown mice were used for ischemia treatment. Right femoral arteries were catheterized with polyethylene catheters for bleeding 50% of total blood volume (≈7% of weight). The ischemia time started to calculate after the model was established. A laparotomy was then carried out to obtain superior mesenteric artery tissues (SMAs) for transcriptome analysis. Series-Cluster analysis was performed to identify the global trends of mitochondrial DEGs after Drp1 knockdown. Gene ontology (GO) analysis was performed to facilitate elucidating the biological process (BP), molecular function (MF) and cellular component (CC) of unique genes in the significant or representative profiles. Results:In addition to its traditional roles in GTPase regulation and mitochondrial fission, Drp1 may also regulate actin cytoskeleton and the movement of microtubules. Besides, Drp1 may participate in the regulation of morphology and functions of other organelles, including endoplasmic reticulum, peroxisome, phagolysosome, etc. As for general organ functions, Drp1 may regulate vascular constriction and dilation. These consequences indicated the important role of Drp1 in ischemia-induced cellular regulation. Conclusions: Drp1 deficiency proves the important role of Drp1 in ischemia-induced biomedical processes through multiple potential fission-independent manners. Methods:C57BL/6 mice and Drp1 knockdown mice were used for ischemia treatment. Right femoral arteries were catheterized with polyethylene catheters for bleeding 50% of total blood volume (≈7% of weight). The ischemia time started to calculate after the model was established. A laparotomy was then carried out to obtain superior mesenteric artery tissues (SMAs) for transcriptome analysis. Series-Cluster analysis was performed to identify the global trends of mitochondrial DEGs after Drp1 knockdown. Gene ontology (GO) analysis was performed to facilitate elucidating the biological process (BP), molecular function (MF) and cellular component (CC) of unique genes in the significant or representative profiles. Results:In addition to its traditional roles in GTPase regulation and mitochondrial fission, Drp1 may also regulate actin cytoskeleton and the movement of microtubules. Besides, Drp1 may participate in the regulation of morphology and functions of other organelles, including endoplasmic reticulum, peroxisome, phagolysosome, etc. As for general organ functions, Drp1 may regulate vascular constriction and dilation. These consequences indicated the important role of Drp1 in ischemia-induced cellular regulation. Conclusions: Drp1 deficiency proves the important role of Drp1 in ischemia-induced biomedical processes through multiple potential fission-independent manners.

Dataset Information

MTORC2-NDRG1-Cdc42 axis couples fasting to mitochondrial fission

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure