mTORC2-Akt signalling localizes to mitochondria-associated ER membranes to regulate mitochondrial function.
| Evidence tier | D Mechanistic / in vitro / review |
| Study type | 5 - Mechanistic / In Vitro |
| Model system | Mammalian cells |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Year | 2013 |
| Peer reviewed | Yes |
| Source | DOI 10.1073/pnas.1302455110 · PMID 23852728 · Free full text (PMC3732980) |
The target of rapamycin (TOR) is a highly conserved protein kinase and a central controller of growth. Mammalian TOR complex 2 (mTORC2) regulates AGC kinase family members and is implicated in various disorders, including cancer and diabetes. Here we report that mTORC2 is localized to the endoplasmic reticulum (ER) subcompartment termed mitochondria-associated ER membrane (MAM). mTORC2 localization to MAM was growth factor-stimulated, and mTORC2 at MAM interacted with the IP3 receptor (IP3R)-Grp75-voltage-dependent anion-selective channel 1 ER-mitochondrial tethering complex. mTORC2 deficiency disrupted MAM, causing mitochondrial defects including increases in mitochondrial membrane potential, ATP production, and calcium uptake. mTORC2 controlled MAM integrity and mitochondrial function via Akt mediated phosphorylation of the MAM associated proteins IP3R, Hexokinase 2, and phosphofurin acidic cluster sorting protein 2. Thus, mTORC2 is at the core of a MAM signaling hub that controls growth and metabolism.
| Intervention | Biochemical/genetic (mTORC2) |
| Target | mTORC2 / Akt / MAM |
| Model | Mammalian cells |
| Effect | mTORC2-Akt localizes to mitochondria-associated ER membranes (MAM) to regulate mitochondrial physiology |