AKT-mediated phosphorylation of TSC2 controls stimulus- and tissue-specific mTORC1 signaling and organ growth
- PMID: 40480230
- PMCID: PMC12258181
- DOI: 10.1016/j.devcel.2025.05.008
AKT-mediated phosphorylation of TSC2 controls stimulus- and tissue-specific mTORC1 signaling and organ growth
Abstract
Mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) integrates diverse growth signals to regulate cell and tissue growth. How the molecular mechanisms regulating mTORC1 signaling-established through biochemical and cell biological studies-function under physiological states in specific mammalian tissues is undefined. Here, we characterize a genetic mouse model lacking the five phosphorylation sites on the tuberous sclerosis complex 2 (TSC2) protein through which the growth factor-stimulated protein kinase AKT can activate mTORC1 signaling in cell culture models. These phospho-mutant mice (TSC2-5A) are developmentally normal but exhibit reduced body weight and the weight of specific organs, such as the brain and skeletal muscle, associated with cell-intrinsic decreases in growth factor-stimulated mTORC1 signaling. The TSC2-5A mice demonstrate that TSC2 phosphorylation is a primary mechanism of mTORC1 regulation in response to exogenous signals in some, but not all, tissues and provide a genetic tool to study the physiological regulation of mTORC1.
Keywords: PI3K; RHEB; feeding; insulin; lean mass; lysosome; microcephaly; myotubes; neurons; phosphoinositide 3-kinase.
Copyright © 2025 Elsevier Inc. All rights reserved.
Conflict of interest statement
Declaration of interests M.S. reports grants from Biogen, Astellas, Bridgebio, and Aucta; past Scientific Advisory Boards (SABs) for Roche, SpringWorks, and Alkermes; and current SABs for Neurogene, Jaguar Gene Therapy, and Noema.
Update of
-
AKT-mediated phosphorylation of TSC2 controls stimulus- and tissue-specific mTORC1 signaling and organ growth.bioRxiv [Preprint]. 2024 Sep 23:2024.09.23.614519. doi: 10.1101/2024.09.23.614519. bioRxiv. 2024. Update in: Dev Cell. 2025 Oct 6;60(19):2544-2557.e7. doi: 10.1016/j.devcel.2025.05.008. PMID: 39386441 Free PMC article. Updated. Preprint.
References
-
- Navé BT, Ouwens DM, Withers DJ, Alessi DR, and Shepherd PR (1999). Mammalian target of rapamycin is a direct target for protein kinase B: identification of a convergence point for opposing effects of insulin and amino-acid deficiency on protein translation. Biochem. J. 344, 427. 10.1042/0264-6021:3440427. - DOI - PMC - PubMed
-
- Sekulić A, Hudson CC, Homme JL, Yin P, Otterness DM, Karnitz LM, and Abraham RT (2000). A direct linkage between the phosphoinositide 3-kinase-AKT signaling pathway and the mammalian target of rapamycin in mitogen-stimulated and transformed cells. Cancer Res. 60, 3504–3513. - PubMed
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Molecular Biology Databases
Miscellaneous
